Undercover Zest
An independent software studio, founded in February 2026 by Luke David in the United Kingdom.
Undercover Zest makes native apps for Mac, iPhone and iPad, and free web tools for songwriters. Every product is specified, built and tested in-house, with Anthropic's Claude Code as the engineering engine: the specification is written first, Claude Code builds to it, and each release is tested on real devices in numbered rounds before it ships. The apps have no user accounts and no analytics.
Products
Rein
One menu-bar panel for the controls macOS hides: keep-awake with the lid closed, fan curves, per-app audio, display brightness, casting, menu-bar tidying, and an iPhone remote.
Rein Remote for Mac
The companion to Rein: put your Mac to sleep, see its screen and use its mouse and keyboard from your phone, on any network.
Leaf – PDF Editor
A PDF viewer and editor for iPhone, iPad and Mac.
Golden Hour Focus
Focus audio for deep work, generated on the device.
Eyeline
A speed-reading app for iPhone and Mac.
Songwriting suite
Five browser tools for songwriters: Chord Progression Builder, RhymeForge, CollisionLab, Morning Pages and SenseSpark.
The App Store apps are published under the developer name Luke David.
Timeline
- February 2026 — Undercover Zest founded; undercoverzest.app registered.
- July 2026 — Rein released for Mac.
- August 2026 — Golden Hour Focus, Eyeline and Rein Remote for Mac released on the App Store.
- September 2026 — Leaf – PDF Editor released on the App Store.
- October 2026 — Rein 1.0, followed by updates for macOS 27.
Company details
- Name
- Undercover Zest, the trading name of Luke David, a sole trader in the United Kingdom
- Founded
- February 2026
- Founder
- Luke David (LinkedIn)
- luke@undercoverzest.app
- Address
- Suite 691, 80A Ruskin Avenue, Welling DA16 3QQ, United Kingdom (letters only)
- Funding
- Self-funded