No feed, no streak, no animation. Sets and weights in three taps, a rest timer that buzzes, and a history chart per exercise: a notebook that records and then gets out of the way.

Habitica wraps habits, dailies and one-off to-dos inside a role-playing game: finish something real, earn experience and gold, level the avatar up, and join party quests where a slacking teammate costs everyone health. Core features stay free and the code stays open.

Most habit apps pile on tasks, points, levels and leaderboards, and the longer the feature list the more effort it takes to keep going. Tickmate goes the other way: one habit, one cell per day, tap it if you did the thing. Streaks, weekday distribution and a histogram come along, the data stays on the phone, and no account is involved.

Fossify Calendar keeps events on the phone, asks for no extra permissions and collects nothing, while still offering repeat rules, layered reminders, four views and calendar protocol sync.

Etar is a calendar for Android published under GPL-3.0 and kept by a community. It has no account system and no cloud of its own; it reads the system calendar database, shows what is already synced in a Material Design interface, and can also hold calendars that exist only on the device.

Loop Habit Tracker is an Android habit app maintained by one independent developer and published under the GPLv3. It has no advertising, no in-app purchases and no account, and it computes habit strength by exponential smoothing instead of resetting a streak to zero.

One of a family of privacy-minded Android tools built by a German university research group: several lists, grouping by aisle, quantities and units, priority marks, reminders, usage statistics and text export. No permissions, no advertising, no tracking.

A free expense tracker for Android, iOS and the web, built by an independent developer and published with its code visible. It offers five ways to sync, from the system cloud to WebDAV, S3 or a self-hosted backend, so the ledger lives on storage you picked rather than on someone else's server.