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Open to work · Berlin · Remote: Europe, UK, Australia, NZIntel-certified in AI

Walid Islam

I build mobile apps people download, pay for and keep using.

Founder of Berlin ArtWalk, Barcelona Art Walk, Nature Unlock, Nibbl and BULU, all live on the App Store and Google Play. Lead developer of the INU university app. Available for mobile engineering and product roles, from hands-on engineer to lead and freelance projects: Berlin, remote across Europe, the UK, Australia and New Zealand.

  • Flutter
  • Swift
  • Kotlin
  • Supabase
  • Firebase
  • Laravel
  • RAG · OpenAI · Gemini
  • RevenueCat
  • Cloudflare
See my work View CV
Walid Islam
Walid IslamBerlin, DE · Remote worldwide
M
Worked withINUcore sensing GmbHComploriShoppium

Projects

Explore my latest work showcasing mobile development expertise.

Top ranked

Berlin ArtWalk

Berlin, explained as you walk it. A full travel guide.

My role: Founder, sole developer

The problem
Berlin has thousands of murals and landmarks but no up-to-date guide that works offline, on foot, in one app.
What I built
Started as a street-art map, now a complete Berlin travel guide: audio guides at 100 landmarks, 8 curated audio walks, turn-by-turn self-guided tours, AI-built routes, a daily what's-on feed, 215+ galleries with current exhibitions and 450+ street-art spots checked by locals. Flutter on Firebase with Google Maps and Gemini.
Result
10,000+ downloads, 4.6+ rating, #1 App Store result for 'Berlin street art' and top 10 for 'Berlin travel guide' (DE, Oct 2026). Grew from one map into audio tours, events and galleries, and the same engine now powers Barcelona.
Audio GuidesWalking ToursEvents Feed215+ Galleries450+ Street ArtOffline Maps
FlutterFirebaseGoogle MapsGemini AIRevenueCatAudio
Website iOS Android
10K+Downloads
4.6+Rating
#1App Store: Berlin street art
Top 10App Store: Berlin travel guide
Berlin ArtWalk
Featured

Nature Unlock

Touch Grass to Unlock Your Phone.

My role: Founder, sole developer

The problem
Screen-time blockers are easy to dismiss. Users wanted a lock that only opens when they actually go outside.
What I built
Locks distracting apps until you photograph real nature, with AI checking the photo is genuine. Scroll Blocker for Reels, Shorts and TikTok, Focus Mode sessions, website blocking, streaks and a screen-time heatmap, guided breathing and AI meditations. Flutter with native Swift and Kotlin on Supabase.
Result
4.8 rating on the App Store and featured on Product Hunt. Needed native Screen Time (iOS) and accessibility (Android) code that Flutter alone can't reach.
Nature Photo UnlockScroll BlockerFocus ModeWebsite BlockingStreaksMeditation
FlutterSwiftKotlinSupabaseGoogle Vision API
Website iOS Android
4.6+Rating
Free + PremiumModel
FeaturedProduct Hunt
Nature Unlock
New Launch

Nibbl

Read What Matters. One Swipe at a Time.

My role: Founder, sole developer

The problem
Newsletters pile up in inboxes and RSS readers feel like work, so people skim or unsubscribe.
What I built
Newsletters and RSS feeds become a swipeable card deck: a personal @nibbll.app inbox (Cloudflare Email Routing → Email Worker → Supabase Edge Function → Postgres with RLS and full-text search), Gmail API ingestion with 300+ filter rules, Gemini AI summaries with a feedback loop, OPML import, highlights, offline library and real-time sync. Flutter for iPhone, iPad and Android, lifetime Pro via RevenueCat.
Result
Live on the App Store and Google Play in seven languages with a paid lifetime tier. Launched 2026 and growing through paid social campaigns I run myself.
Swipe CardsAI SummariesCloudflare InboxGmail ImportRSS + OPMLOfflineiPad
FlutterDartSupabaseCloudflare WorkersPostgresRevenueCatGemini AIGmail API
Website iOS Android
7Languages
Free + Lifetime ProModel
Feb 2026Launched
Spin-off

Barcelona Art Walk

Everything to do in Barcelona. A full travel guide.

My role: Founder, sole developer

The problem
Berlin ArtWalk worked. The question was whether the product could become a platform: a second city without rebuilding the app.
What I built
Barcelona travel guide: 300+ artworks, galleries and museums on one map, audio tours at 89 landmarks including the Gaudí route, daily events, turn-by-turn walking tours. Same Flutter engine as Berlin ArtWalk, re-skinned and re-launched in weeks.
Result
Launched January 2026 with about 90% of the codebase shared with Berlin; already a top 10 App Store result for 'Barcelona city guide' (DE, Oct 2026). Proof that the next city costs weeks, not months.
300+ Artworks89 Audio ToursGaudí RouteEvents FeedGalleriesTurn-by-turn
FlutterFirebaseGoogle MapsAudioRevenueCat
Website iOS Android
Top 10App Store: Barcelona city guide
Jan 2026Launched
~90%Reused code
New launch

BULU: Pet Care & Vet Finder

Pet care, vets and places, on one map.

My role: Founder, sole developer

The problem
Pet owners in Malaysia and Singapore find vets, groomers and pet-friendly places through scattered Facebook groups and word of mouth.
What I built
Pet-care app for Malaysia and Singapore: vets, groomers, pet hotels and pet-friendly cafés on one map, pet profiles with care reminders, health records and weight log, a community feed and a Gemini-powered care assistant. Flutter on Firebase with Google Maps, RevenueCat and AdMob, plus a Flutter Web admin panel and a Next.js marketing site.
Result
Launched August 2026 on the App Store and Google Play with a 5.0 App Store rating at launch. Built on the ArtWalk engine, so map, places, events and community came almost for free; pet profiles, reminders, health records and the AI assistant are new.
Vet & Clinic FinderPet ProfilesCare RemindersHealth RecordsCommunityGemini Assistant
FlutterFirebaseGoogle MapsGeminiRevenueCatAdMobFlutter Web admin
Website iOS Android
5.0App Store rating
Aug 2026Launched
MY · SGMarkets

Impactful Projects

Featured

INU University App

Central learning hub of INU, Germany's innovative online university: course material, offline study, coursework and AI tutoring on iOS, Android, iPad and web from one Flutter codebase. Lead developer; Laravel backend, Vue.js admin, RAG on Azure AI Studio and OpenAI.

FlutterLaravelVue.jsAzure AI StudioRAGOpenAI
Website
Featured

ZenScript

Android digital-wellbeing app that turns doomscrolling into reading time. Uses native Android usage-access and accessibility APIs to block distracting apps on a timer, with a built-in ebook reader and mindfulness tools. Built with Flutter and native Kotlin.

FlutterKotlinApp Usage APIDigital Wellbeing
Android
Featured

Medical Hive

Exam-prep platform for medical students: interactive quizzes, spaced practice and progress tracking, backed by a question-bank API and analytics. MedTech / EdTech work alongside the consumer apps.

FlutterFirebaseBloc/CubitCloud Functions

Additional Projects

  • core sensing Sensor AppIndustrial IoT app that streams, charts and records data from up to four measuring amplifiers over Bluetooth Low Energy with protobuf, plus CSV export and a Patrol test suite.FlutterBLEProtobuf
  • Complori Coding AppGamified Flutter app teaching children aged 10 to 16 to code alongside live coaching; Firebase, Cloud Functions, child-friendly UX and widget tests.FlutterFirebaseCloud Functions
  • Admin dashboardsFlutter Web back-offices for Berlin ArtWalk, Barcelona Art Walk and BULU: content and event management with a rich-text editor, map pickers, push campaigns and charts on Firebase.Flutter WebFirebaseMobX
  • Max und MimiGerman-learning story app for beginners: an interactive story about Max and his cat Mimi teaches vocabulary in context. Flutter for iOS, Android and macOS, in development.FlutteriOSAndroid
  • Berlin BuzzBerlin-based blog app for food, events, and local experiences with real-time updates and social features.FlutterLaravelNext.js
  • ShoppiumE-commerce platform with advanced shopping features, real-time updates, and seamless payment integration.FlutterFirebaseCloud Firestore
  • WordzzleEngaging word puzzle game with unique gameplay mechanics and social features.FlutterHive DBOneSignal

What I can build for you, at a glance

Full tech stack ↓

Mobile apps

  • Flutter & Dart
  • Swift (iOS)
  • Kotlin (Android)
  • React Native
  • Flutter Web
  • Bloc, MobX, GetX
  • Offline-first, Hive, SQLite
  • 7-language i18n

Backend & infrastructure

  • Supabase (RLS, RPC, edge functions)
  • Firebase (Firestore, Functions, App Check)
  • Laravel (Sanctum, Horizon, JSON:API)
  • PostgreSQL, Redis
  • REST & GraphQL
  • Cloudflare Email Routing & Workers
  • Postgres full-text search, triggers
  • Docker, Vercel
  • Rust via flutter_rust_bridge

AI features

  • RAG pipelines
  • OpenAI & Azure AI Studio
  • Google Gemini
  • ML Kit & Google Vision
  • LLM summaries with feedback loop
  • AI chat UIs
  • Intel-certified in AI (ML, CV, NLP)

Native, devices & integrations

  • iOS Screen Time API
  • Android usage & accessibility
  • Bluetooth Low Energy, protobuf
  • Google & Apple Maps, GPS, routing
  • Gmail API & newsletter ingestion
  • Push, OneSignal, Live Activities
  • Background tasks, WorkManager
  • Audio, video, PDF, EPUB

Monetisation & growth

  • RevenueCat subscriptions & paywalls
  • AdMob, Stripe
  • App Store & Play publishing
  • ASO & competitor research
  • Meta/Instagram ads & attribution
  • PostHog, Firebase & Sentry
  • Product Hunt launches
  • Unit economics & pricing

Quality & operations

  • Unit, widget & bloc tests
  • Patrol & integration tests
  • CI/CD, FVM, codegen
  • Crash triage (Sentry)
  • Security audits (RLS, advisors)
  • GDPR & account deletion flows
  • Accessibility
  • Next.js landing pages

Like what you see? I'm available for mobile engineering and product roles, from hands-on engineer to lead, plus freelance projects.

View CV

What people say

Public App Store reviews of the apps I built, quoted word for word, plus recognition you can check.

  • “This app certainly brings an integrative pet friendly platform to the Malaysian market that has never been done before. It's a one-stop platform for pet owners in Malaysia! Love it.”
    milikonokoApp Store review, MalaysiaBULU
  • “I was also struggling to reduce my screen time, and thanks to this app, I've now made progress. Highly recommended!”
    DenSim26App Store review, GermanyNature Unlock
  • “Such a unique way to explore Berlin.”
    Abantyx2App Store review, GermanyBerlin ArtWalk
  • “Very useful and easy to use. It makes pet care simple and convenient.”
    FaisalrckApp Store review, MalaysiaBULU

Recognition

Intel Digital Readiness Lead Facilitator Certificate for Walid Islam, AI for Future Workforce Program, Germany, 15 July 2026View PDF
Intel certification

Intel-certified in AI

Lead Facilitator, AI for Future Workforce Program · Intel Digital Readiness · Germany, July 2026

Trained and certified by Intel in applied AI: machine learning, deep learning, computer vision, NLP and AI solution building, plus training other facilitators. For private and public universities, Hochschulen and EdTech teams that need someone who can both ship AI features and teach them to staff and students.

  • Machine Learning
  • Deep Learning
  • Computer Vision
  • NLP
  • AI Solution Building
  • AI Ethics
  • Python
  • Facilitation
Open the certificate (PDF) Badge definition on Credly

ID AI4FWFGERIRL0726005

How I make your product better

Six things I do that show up in downloads, revenue and retention, each already proven in an app I shipped.

  • Ship to both stores, fast

    One Flutter codebase for iOS, Android and iPad, native Swift or Kotlin only where the platform demands it. Fewer engineers, one release train, no feature drift between platforms.

    Proof: Barcelona Art Walk re-used the Berlin ArtWalk codebase and launched in weeks. Five apps live in both stores.

  • Turn users into revenue

    Subscriptions, lifetime purchases and ads with RevenueCat and AdMob, paywalls that convert without annoying free users, and pricing per market.

    Proof: Nibbl free tier plus lifetime Pro, Nature Unlock Premium subscription, Berlin ArtWalk ads and vendor promotion.

  • Keep them coming back

    Streaks, push notifications, daily content, offline mode and Live Activities, all measured with analytics so we keep what works.

    Proof: Nature Unlock streaks and Live Activity, Berlin ArtWalk daily what's-on feed, Nibbl's Today's Headlines.

  • AI that earns its place

    LLM summaries, computer vision, RAG over your own content and AI-generated routes or meditations, scoped so it is useful and affordable, not a gimmick.

    Proof: Nibbl Gemini summaries, Nature Unlock on-device ML Kit photo verification, INU RAG tutoring, ArtWalk AI-built tours. Intel-certified AI facilitator.

  • Launch and grow, not just build

    Store listings and screenshots that convert, Product Hunt launches, Meta, Instagram and Reels ad creatives, landing pages and event tracking.

    Proof: Three Product Hunt launches, paid campaigns for Nibbl, four landing pages, 10,000+ downloads.

  • Native where it matters

    Screen Time and accessibility APIs, Bluetooth Low Energy, protobuf streams and background work, covered by unit, widget and Patrol tests so releases don't break.

    Proof: Nature Unlock and ZenScript app blocking, core sensing BLE sensor dashboards with a Patrol test suite.

Who I work with

Four kinds of people land here. Each gets someone who has already shipped what they need.

Scale-ups & product companies

Scale-ups and product companies in Germany, Europe, the UK, Australia and New Zealand hiring mobile engineers, product-minded engineers or technical product managers, from hands-on roles to lead.

  • Five consumer apps live in both stores, built solo end to end. I have owned the roadmap, the code, the store listing and the P&L, not just the ticket.
  • Product sense with numbers: paywalls, pricing, retention loops, unit economics and ad campaigns run on my own apps, measured with PostHog and Firebase.
  • Team experience at INU (lead developer), Complori (EdTech), core sensing (industrial IoT) and Shoppium (e-commerce): reviews, tests, releases, stakeholders.
  • Full stack when needed: Supabase, Firebase, Laravel, REST and GraphQL, Cloudflare Workers, native Swift and Kotlin where the platform demands it.
  • Berlin-based, German and English, remote or hybrid, used to working across time zones (built apps for Malaysia and Singapore, studied and worked in New Zealand). Roles: Mobile or Flutter Engineer, Flutter Lead, Technical Product Manager. Willing to relocate within Europe or to the UK, Australia or New Zealand with visa sponsorship and relocation support.
Hire me

Universities & EdTech

Private and public universities, Hochschulen and EdTech teams in Germany, Europe, the UK, Australia and New Zealand hiring for a campus app, learning platform or AI tutor.

  • Lead developer of the INU university app: one Flutter codebase on iOS, Android, iPad and web, offline course material, used by students every day.
  • AI tutoring in production: RAG pipelines on Azure AI Studio and OpenAI, plus the groundwork for AI professor avatars.
  • EdTech for kids at Complori: gamified coding lessons, Firebase backend, child-safe UX, unit and widget tests.
  • Medical Hive: quiz and spaced-practice app for medical students, backed by a question-bank API.
  • Intel Digital Readiness certified Lead Facilitator for the AI for Future Workforce program (2026), so I can teach AI as well as build it. Accessible, GDPR-conscious, bilingual.
Talk about your campus app

Investors & partners

Angel investors, studios and startups anywhere looking at consumer apps with traction, or a city-guide engine to license for a new city.

  • Five live products with real users: Berlin ArtWalk (10K+ downloads), Nature Unlock, Nibbl, Barcelona Art Walk and BULU, all founder-built and self-funded.
  • Proven playbook: the ArtWalk engine launched a second city in weeks and a pet-care app in a new market. Next cities and verticals are a content job, not a rebuild.
  • Revenue in place: subscriptions and lifetime purchases via RevenueCat, AdMob, vendor promotion. Unit economics modelled per app.
  • Open to: angel or pre-seed investment in Nibbl, Nature Unlock or BULU, white-label or licensing of the ArtWalk city-guide engine, and technical co-founder or partnership roles in AI-first consumer products.
  • Lean by design: one engineer, low infra cost (Supabase, Cloudflare, Firebase), AI features scoped to stay profitable per user.
Talk about a partnership

Founders & businesses

Freelance, worldwide: you bring the idea, I deliver a published app and the growth around it.

  • MVP in 6 to 12 weeks. iOS and Android from one Flutter codebase, native Swift or Kotlin where the platform demands it.
  • Backend included: Supabase, Firebase or Laravel, auth, subscriptions (RevenueCat), push notifications, deep links.
  • I publish it: App Store and Google Play listings, screenshots, review handling, staged releases.
  • Then I grow it: landing page, Meta, Instagram and Reels ad creatives, analytics and event tracking.
  • Proof: Nibbl, Nature Unlock and Berlin ArtWalk were built, launched and marketed by me alone.
Start a project

Experience

My professional journey in mobile and full-stack development.

  • •Lead development of the INU App, a cross-platform mobile application (iOS, Android, iPad, tablet & Web app) serving as the central learning hub for Germany's innovative online university
  • •Architect and implement AI-powered educational features using Retrieval-Augmented Generation (RAG) pipelines integrated with Azure AI Studio and OpenAI APIs
  • •Developed the technology foundation for AI-based professor avatars providing 24/7 student support with interactive, on-demand learning assistance
  • •Build and maintain full-stack solutions using Flutter/Dart for mobile, Vue.js for Admin, and Laravel backend services with REST APIs
  • •Leverage Microsoft Azure ecosystem including Azure Data Factory and Azure Machine Learning for data pipelines and ML model deployment
  • •Design intuitive UI/UX following iOS Design Guidelines and Material Design principles for diverse student populations
  • •Collaborate with academic teams to translate pedagogical requirements into technical solutions supporting accessible, AI-enhanced education
FlutterDartRetrieval-Augmented Generation (RAG)Azure AI StudioOpenAI APIsVue.jsLaravelREST APIs

Earlier: Customer Support Analyst, 2degrees (Nov 2019 - Nov 2020) · Software Asset Management Consultant, Accordo Group Ltd. (Oct 2018 - Jul 2019)

Tech Stack

Everything I ship with, grouped by what it is for.

Flutter

Daily Driver

Dart

Core

iOS / Swift

Go-To

Android / Kotlin

Reliable

React Native

Rock Solid

Bloc / Cubit + Hydrated Bloc

Essential

MobX, GetX, Provider

Game Changer

get_it / injectable DI

MVP

go_router

Fav

Push & Deep Links

Trusted

Offline-first (SQLite, Hive)

Bread & Butter

i18n (slang, 7 languages)

Power Tool

Lottie & Animations

Chef's Kiss

Flutter Web admin panels

Workhorse

Audio: background playback & recording

Go-To

Video: player, streaming, FFmpeg

Reliable

PDF & EPUB readers, PDF generation

Core

Markdown, LaTeX & rich text

Trusted

QR codes, image compression, BlurHash

Daily Driver

Services

Freelance: from idea to a published app, plus the marketing that gets it downloads.

Why Choose Me?

Full-Stack Mobile Engineer

5+ years shipping production apps across Flutter, native iOS (Swift) and Android (Kotlin), with backends and AI integrations.

End-to-End Solutions

From product design and UI/UX to app, backend, AI features, release and maintenance.

Quality & Performance

High-performance, maintainable, scalable apps with clean architecture.

Flexible Engagement

Available for full-time, part-time, or project-based collaborations.

Cross-Platform Apps (Flutter)

Cross-Platform Apps (Flutter)

Native iOS Development (Swift)

Native iOS Development (Swift)

Native Android Development (Kotlin)

Native Android Development (Kotlin)

Backends: Laravel, Supabase & Firebase

Backends: Laravel, Supabase & Firebase

AI & RAG Integration

AI & RAG Integration

UI/UX Design

UI/UX Design

Push Notifications & Deep Linking

Push Notifications & Deep Linking

BLE & Device Integrations

BLE & Device Integrations

App Store & Play Publishing

App Store & Play Publishing

App Architecture & Scaling

App Architecture & Scaling

Performance Optimization

Performance Optimization

Technical Consulting

Technical Consulting

From Code to Market

I handle the full journey: designing and building the app (Flutter or native iOS/Android), the backend and AI features, then publishing to the App Store and Google Play, plus landing pages and ad campaigns when you need them.

App Store Connect
Facebook Ads
Instagram Ads
Reels Ads

Hire Me

Open to mobile engineering and technical product roles, from hands-on engineer to lead (full-time or contract), freelance app projects, and investment or partnership talks on my apps. Based in Berlin; remote across Europe, the UK, Australia and New Zealand, or relocating with visa sponsorship and relocation support.

5+ YearsExperience
10K+Downloads
15+Published Apps
10+Technologies
Full-timeContractFreelanceRemoteRelocation with visa & relocation supportIntel certified: AI for Future Workforce lead facilitator
LinkedInEmailXINGMMaltView CV

FAQ

What recruiters, universities and founders ask before they get in touch.

All three. Walid Islam is based in Berlin and open to mobile engineering roles from hands-on engineer to lead (full-time or contract) with product companies, universities and EdTech teams, hybrid or remote across Europe, the UK, Australia and New Zealand, and to freelance app projects delivered end to end. Reach him via the contact form, LinkedIn or Malt.