Is my data stored in the cloud?
No Kinoku server stores your training history, and core features run on your phone. Android's own backup may copy eligible app data to your Google account.
Kinoku has no account to sign up for, and no Kinoku server stores your training history. Logging, routines, stats and the math behind them all run on your phone, so they keep working with no internet.
One copy may exist that you did not make yourself. When Android system backup is on, Android can copy eligible app data to your Google account, as it does for most apps. Your cycle records are the one part it leaves out, because they sit in a database of their own.
A few features go online for a set reason. Map tiles load from the web, Google Play checks your plan, and YouTube sends video details when you add a link. Diagnostics stay off until you turn on Help improve Kinoku in Settings, under Privacy & Data Use. Once on, they can send rough details, such as whether a workout started and how long it ran. Diagnostics never send exercise names, set logs, notes, routes, Health Connect values, cycle data or photos.
The privacy policy names each outside service the app can reach, and the data sovereignty page explains why it is built this way.