Kalm

Problem

The iPhone lock screen offered little glanceable context beyond the time. Users needed useful information without having to unlock their device.

Role and scope

I designed the interface and built the tweak in Objective-C, covering the experience from visual direction through implementation.

Key decisions

• Keep weather and upcoming events visible without competing with the clock.
• Adapt the interface colours to each wallpaper so the tweak feels native to the lock screen.
• Use a restrained layout that remains legible across very different backgrounds.

Outcome

Kalm became a commercial jailbreak tweak and generated approximately 25,000 sales.