If you have enabled the stopwatch in the web version of TimeLog, you can also use it in the app.
In TimeLog for web, you or your system administrator need to enable it in the system administration under Time and expense registration -> Time tracking setup:
Then you need to enable it in your personal settings for the timesheet. You first click the gears icon, and then you have the option to select your personal settings.
You find the setting in the app under Settings:
Please note: You need version 1.0.6 or higher of the app to be able to use the stopwatch there too.