timeto.me app
timeto.me is Time tool that is open source under the GPL-3.0-or-later license. The main feature of this app is there is no "stop" option. Once you have completed one activity, you have to set a timer for the next one, even if it's a "sleeping" activity.This time-tracking approach provides real 24/7 data on how long everything takes. You can see it on the Chart screen. It's always surprising.
By default, the app contains the activities that I use: meditation, work, music, personal development, exercises, walk, getting ready, sleep / rest, other. That's all I need, but you can change it.