A free app for Android, by EzyInfo.
Floating Stopwatch & Timer is a free, simple, easy-to-use stopwatch and timer app that displays the time on your screen, no matter what application you are using. It is always on top of the screen, so you can keep track of time even when you are using other apps.
To start or pause, tap once on the stopwatch or tap and hold on the timer. To hide, just go back to the application and press the button again or slide it to the right of the screen.
The stopwatch can be used for speeches, cooking, JW meetings, and other situations where you need to keep time on your screen.