Freelance Mobile App Developer (iOS / Android)

Remote from: Germany
Salary, yearly, USD: 120,000
Department: Programming
Employment type: Full Time,
Job posted: 8 Jun 2026
Apply before: 8 Jul 2026
Experience level: Midweight
Views / Applies: 27 / 8

Mindrift connects AI experts and clients to advance Generative AI models.

Actively Hiring

AI Summary

Mindrift is seeking freelance Mobile App Developers with 3+ years of experience in native (Swift, Kotlin) or cross-platform (React Native, Flutter) frameworks to join the Tendem project. As an AI Pilot, you will build and refine mobile applications, integrate device features and backend APIs, and evaluate AI-generated code. The role offers a part-time remote schedule with 10-20 hours per week during active phases, ideal for self-directed professionals who can deliver production-ready apps. Compensation is competitive, with a minimum salary of $120,000 annually.

Role DNA

Job Complexity

Easy Hard

Pace & Pressure

Relaxed Fast-paced

Autonomy Level

Guided Full Ownership

Communication Load

Independent Highly Collaborative

AI Insight The role requires 3+ years of experience and a strong command of mobile development frameworks, but the project-based nature and AI-assisted environment keep the difficulty moderate.

Salary Analysis

AI Insight The offered salary of $120,000 is competitive for a freelance mobile developer with 3+ years of experience, falling near the median of the US market range ($90k-$160k). While the lack of a confirmed maximum leaves room for negotiation based on performance and project scope, the base compensation is attractive for the flexibility of part-time remote work.

Key Skills

React Native Flutter Swift Kotlin iOS Android Mobile UI REST APIs Firebase Git

Cover Letter Sample

Dear Hiring Team,

I am writing to express my interest in the Freelance Mobile App Developer role at Mindrift. With over 4 years of experience building cross-platform apps using Flutter and React Native, I am confident in my ability to contribute to the Tendem project. My portfolio includes several published apps on both App Store and Google Play, demonstrating my proficiency in implementing responsive UIs, integrating device APIs, and managing local storage.

I thrive in self-directed environments and am experienced in collaborating with AI-powered tools to streamline development. My technical expertise also extends to REST API integration, Firebase backends, and performance optimization, ensuring deliverable quality. I am excited about the opportunity to work with Mindrift's innovative platform and would love to discuss how my skills align with your needs.

Thank you for your consideration. I look forward to the possibility of contributing to your team.

Possible Interview Questions

Describe your experience with a cross-platform framework. What challenges did you face and how did you overcome them?

I have used Flutter for a travel booking app. One challenge was handling platform-specific UI components like date pickers. I solved this by creating platform channels and using conditional rendering to ensure native look and feel. I also optimized performance by reducing widget rebuilds with const constructors.

How do you approach integrating a new device API (e.g., camera or location) into an existing app?

I start by reviewing the platform's documentation and checking permissions. Then I create a dedicated service class to wrap the API calls. For example, for camera integration, I would use the appropriate library (e.g., CameraX on Android, AVFoundation on iOS) and test on multiple devices. I also handle error cases gracefully.

Explain your process for refactoring AI-generated code for performance and maintainability.

First, I review the code for potential bottlenecks like unnecessary loops or database queries. I then refactor by extracting reusable functions, adding comments, and following clean architecture principles. For mobile, I also check for leaks (like unclosed StreamControllers) and ensure efficient rendering.

How do you ensure your app works offline? Give a specific example.

I implement a local database (like SQLite via Room or Core Data) to cache data. In a delivery app, I used a repository pattern that first fetches data from the local cache, then syncs with the remote server when online. I also used WorkManager to schedule background syncs.

What is your experience with app store submission processes? How do you handle rejections?

I have submitted apps to both App Store and Google Play. For rejections, I carefully read the feedback and address the specific issue. For example, if an app is rejected for lacking a privacy policy, I would immediately add it and resubmit. I also ensure compliance with guidelines such as using HTTPS for API calls.

Mindrift is looking for skilled Mobile App Developers (React Native, Flutter, Swift, or Kotlin) to join the Tendem project (https://tendem.ai/) and build native and cross-platform mobile applications within our hybrid AI + human environment. In this role, as an AI Pilot – that’s how we refer to this position at Mindrift – you’ll collaborate with Tendem Agents that handle repetitive tasks, while you provide mobile engineering expertise, platform-specific judgment, and quality control to ensure apps are stable, performant, and ready for real users on real devices. This part-time remote opportunity is ideal for professionals with hands-on experience shipping iOS and/or Android apps, working with platform APIs, and handling the full mobile development lifecycle.

What We Do

The Mindrift platform connects specialists with AI projects from major tech innovators. Our mission is to unlock the potential of Generative AI by tapping into real-world expertise from across the globe.

About the Role

This is a freelance role for a Tendem project. As a Mobile App Developer, you’ll design, build, and refine mobile applications across categories such as utilities, fitness/wellness, games, productivity, delivery, and content apps — for iOS, Android, or both, using native or cross-platform frameworks.

Key Responsibilities

Build mobile applications using React Native, Flutter, Swift (iOS), or Kotlin (Android).
Implement responsive mobile UIs that follow platform conventions (iOS HIG, Material Design).
Integrate native device features (camera, push notifications, location, storage, biometrics).
Connect apps to backend APIs, handle offline state, caching, and synchronization.
Implement monetization features where required (in-app purchases, ads, subscriptions).
Evaluate AI-generated mobile code and refactor it for correctness, performance, battery use, and maintainability.
Debug platform-specific issues and prepare builds for distribution (TestFlight, Play Console).

Requirements and benefits

At least 3 years of relevant experience in mobile app development (required).
Bachelor’s or Master’s Degree in Computer Science, Engineering, Information Technology, or related technical fields is a plus.
Candidates should have a strong foundation in mobile application development, platform-specific UI/UX patterns, and building stable, high-quality mobile experiences for iOS and Android. We are looking for specialists who can confidently work with native or cross-platform frameworks, integrate device APIs and backend services, and refine AI-assisted output into production-ready mobile applications. Strong attention to detail, performance awareness, and the ability to work independently are essential.
Hands-on experience with at least one of: React Native, Flutter, Swift/SwiftUI (iOS), or Kotlin/Jetpack Compose (Android).
Solid understanding of mobile UI patterns, navigation, state management, and platform guidelines.
Experience integrating REST APIs, handling async data, and managing local storage.
Familiarity with native device APIs (notifications, camera, location, storage, biometrics).
Experience with mobile build tools, code signing, and submission to App Store / Google Play.
Experience implementing in-app purchases, ads, or subscriptions is a plus.
Familiarity with backend services such as Firebase, Supabase, or similar is a plus.
Strong attention to detail and commitment to performance, stability, and platform polish.
Self-directed work ethic with the ability to ship complete mobile features independently.
Portfolio of shipped mobile apps (required, with App Store / Google Play links preferred).
English proficiency: Upper-intermediate (B2) or above (required)

Project time expectations

For this project, tasks are estimated to require around 10–20 hours per week during active phases, based on project requirements. This is an estimate, not a guaranteed workload, and applies only while the project is active.

Compensation

On this project, contributors can earn up to $60 per hour equivalent, depending on their level and pace of contribution.

Compensation varies across projects depending on scope, complexity, and required expertise. Please note that other projects on the platform may offer different earning levels based on their requirements.

Why this freelance opportunity might be a great fit for you?

Work fully remote on your own schedule with just a laptop and stable internet connection.
Gain hands-on experience in a unique hybrid environment where human expertise and AI agents collaborate seamlessly — a distinctive skill set in a rapidly growing field.
Participate in performance-based bonus programs that reward high-quality work and consistent delivery.

Apply now >