Why your step counter stopped counting
Short answer: most pedometer apps stop because Android closed them in the background, because they need a START button you forgot to press, or because the phone rebooted. Use a step counter with no start button that keeps an ongoing notification and restarts itself after a reboot.
Cause 1: a START button
Many apps only record after you tap START, and stop when you tap it again by accident. Reviewers say it plainly: "I have to remember to open the app." A pedometer that counts from the phone's step sensor all day does not need one.
Cause 2: battery optimization
Android, and especially some manufacturers, kills apps in the background. An ongoing notification keeps the counter alive. If counting still stops, open Settings, Apps, your pedometer, Battery, and choose Unrestricted.
Cause 3: reboots and updates
The step sensor resets when the phone restarts. A good app starts counting again by itself after a reboot without you opening it.
How to see if steps are missing
Look at a by-hour chart. If a walk you remember shows zero, counting was off. Tallystep stripes the hours when counting was off, so gaps are never silently hidden, and you can set that day's steps by hand.
Doing it with Tallystep
Allow physical activity once. Tallystep has no START/STOP toggle, shows today's steps in an ongoing notification and starts again after a reboot. It works offline with no account.
FAQ
Why does my pedometer stop counting randomly?
Usually Android stops the app in the background to save battery, or the app only counts after you press START. An app that keeps an ongoing notification and has no start button keeps counting.
Why are some hours missing in my step history?
Counting was off in those hours, often after a reboot or when the app was closed. Tallystep marks those hours with stripes so gaps are visible.
Do I need to open the app every day?
Not with a pedometer that reads the step sensor in the background. Allow physical activity once and it counts on its own.