Building a Modern iOS App with CI/CD, Metal GPU, and Advanced Custom UX Controls

What does it take to take an app from concept to shipped product? In this case study, we break down the process behind building Stickah Pro, an iMessage sticker creation app that delivers features far beyond standard App Store tools. This includes solving unique UX challenges, implementing advanced rendering, and building a maintainable CI/CD pipeline for ongoing updates.

Problem

Apple’s native iMessage Sticker framework is extremely limited. It offers no way to:

• Provide fine-grained, precise editing tools
• Allow users to create stickers with inner cutouts or complex shapes
• Support advanced visual effects like transparent alpha channels, gradients, or APNG animation
• Share user-created stickers with friends so they can send them as well

Most sticker apps on the App Store offer only a crude cutout editor and flatten everything into a basic PNG. The challenge was to build a professional-grade editing experience while keeping the UX clean enough for everyday users.

Solution Overview

Stickah Pro was built as a full-featured iOS app with a custom rendering pipeline, advanced editor toolset, and a simple user experience. The app solves all of the limitations above while remaining App Store-compliant.

SpecOps Engineers’ Role

We handled the entire engineering stack end-to-end:

• iOS development (Swift / Objective-C / Metal)
• Core Image + custom graphics pipeline for APNG
• UX design and interaction flows
• Custom UI Control elements vector graphic controls
• GPU powered photoshop style Metal sticker editor
• CI/CD automation with Fastlane and GitHub Actions
• Simple + cost effective secure AWS S3 serverless backend

Technical Approach

The project required custom engineering solutions not available in off-the-shelf libraries:

• Custom Sticker Rendering – Built multiple pipelines supporting layers, inner cutouts, alpha masks, gradients, and animated PNGs.
• Precision Editing Tools – Implemented undo, redo, and sticker preview for highest quality sticker output
• APNG Exporter – Supported smooth animations that retain color depth and transparency.
• Sticker Sharing – Enabled users to create shareable sticker bundles outside the limitations of standard iMessage packs.
• Performance Optimization – Ensured low memory usage even with complex graphics.
• CI/CD Pipeline – Automated builds, signing, and TestFlight releases using Fastlane + GitHub Actions.

Challenges

• Balancing powerful editing tools with a simple UI
• Maintaining 60fps animation previews on older iPhones
• Ensuring APNG compatibility across iMessage, social apps, and third-party platforms
• Managing custom entitlements and provisioning profiles for advanced features

Results

Stickah Pro shipped successfully on the App Store with a polished UX and advanced features rarely seen in iMessage sticker apps. The app consistently receives positive feedback for its ease of use and professional-grade output quality.

• Seamless creation of complex stickers with transparency and animation
• Fast, reliable TestFlight and App Store release pipeline
• Modern, maintainable codebase ready for future expansion
• High user satisfaction due to smooth editing experience

Future Improvements

• Cloud sync for sticker packs
• Template packs and downloadable assets
• Community sharing hub
• AI-powered auto-cutout tool

Summary

Stickah Pro demonstrates our ability to take a highly technical, design-sensitive iOS project from concept to App Store release. It highlights strengths in iOS, graphics programming, UX execution, and DevOps automation—skills that apply directly to modern mobile app development work.