02 / Apps

Apps.

Products we design, build and keep running ourselves.

01 / iOS · Android

Robin.

Life in the UK test practice, told as a journey through the country. iOS and Android. See Robin Launching Oct 2026
Robin, Today screen
02 / Web
C

Corro.

Uptime monitoring checked from independent, distributed nodes. Read the idea In design
Design cardNodes Independent checks {CONCEPT: one sentence on how a check works}
Domaincorro.run
StatusIn design
03 / Web · UK
B

Bookkeeper.

Bookkeeping and Self Assessment tax returns for individuals. Read the idea In design
Design cardUK Self Assessment {CONCEPT: one sentence on how it works}
BookkeepingIndividuals
Tax returnSA100
Notes
SupportWrite to {SUPPORT EMAIL}. The person who built the app answers.
Plain pricingRobin is free. Prices for Corro and Bookkeeper will be published before they open.
Releases

Everything the studio ships

Release notes are written by the person who shipped them.
Oct {D} Robin 1.0iOS and Android · Life in the UK test practice Coming soon
Oct {D} yunfeng.aiWeb · the studio site, in eight languages Launch
2026 Oct Y.F. Zhang & Co. brand system 1.0Brand · logo, type, artefacts, applications Release
2026 Oct Corro and BookkeeperUptime monitoring; personal bookkeeping and tax In design