About the Project

We are looking for an experienced iOS developer to build the iOS version of an existing Android application. The app is a messenger and calling platform with an extreme focus on user security, privacy, and anonymity. The Android version is fully built and functional - your job will be to architect and develop the iOS counterpart that matches its security standards and feature set.
This is not a typical messaging app. The architecture includes blockchain-based user identity (cross-platform module, already built), bitmap-based messaging instead of traditional text transmission, and hardware-leveraged encrypted voice and video calling. iOS and Android users will need to communicate seamlessly with each other.

What You'll Be Building

The iOS app needs to replicate three core systems: a secure messaging pipeline where messages are rendered as bitmaps, encrypted, transmitted, and displayed - never handled as plain text in transit; an encrypted calling system that leverages iOS hardware security capabilities (Secure Enclave, hardware AES) to achieve the same level of protection as the Android version's hardware-based approach; and a security and anonymity layer including anti-tampering, traffic protection, and privacy hardening specific to the iOS platform.
The blockchain identity module is already cross-platform ready and will be integrated, not rebuilt.

This is a contract engagement. We're open to discussing timeline and structure once we've assessed fit.

Required Skills & Experience

  • You must have 5+ years of iOS development with Swift as your primary language
  • Knowledge of Objective-C for bridging C/C++ libraries and legacy APIs.
  • Experience with WebSocket-based real-time communication on iOS.
  • You need strong low-level graphics knowledge with Core Graphics and ideally Metal, as you'll be building or porting a bitmap rendering and processing pipeline that handles encryption-sensitive image data.
  • VoIP development experience on iOS is critical. Whether that's WebRTC, custom protocols, or both - you need to have shipped calling features and worked with CallKit (which Apple mandates for VoIP apps).
  • You should also have practical experience with iOS platform security hardening: jailbreak detection, screenshot/screen recording prevention, disabling iCloud backup for sensitive data, and anti-tampering measures.

Nice to Have

  • Experience with blockchain/Web3 identity systems or wallet-like key management.
  • Familiarity with the Signal Protocol or similar E2E encryption frameworks.
  • Experience with C/C++ library integration via bridging headers.
  • Prior work on apps that have passed App Store review with encryption and anonymous communication features.
  • Experience with security audits or penetration testing on mobile apps.

About the Collaboration

You will have access to the full Android source code and direct communication with the original Android developer for knowledge transfer. The work involves understanding the existing Android architecture, designing the iOS equivalent that maintains protocol compatibility, and building it to the same security standard.

Important Context

Apple has specific requirements around VoIP apps (CallKit integration is mandatory), encryption export compliance declarations, and scrutinizes anonymous communication apps during App Store review. You should be aware of these constraints and ideally have navigated them before.

Perks:
Outgrow your role Show initiative. Build your skills and test your strengths.
Location Work from anywhere. We have beautiful offices in old-town Vilnius when you need to come in.
Flexible working hours Focus your efforts when you are most creative and productive.
Learn all the time Would you like to attend conferences or take paid training? There is a budget for that.
Additional health insurance Take care of yourself. It just makes sense.
Take some time off Take a day off on a short notice. We have all been there. Just be respectful of your responsibilities and to your team.
Pitch your ideas about anything We build startups.
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