Use APKPure App
Get Simple Timer old version APK for Android
Ordentlicher Timer
A very simple timer application that uses a microwave style input method. Nothing fancy, just type in the time you want, press start, and the countdown begins!
The app will cause your phone to vibrate and play your default alarm sound when the alarm finishes.
This app is open source, you can view the source code at https://github.com/Tywholland/SimpleTimer
Also, thanks to Jose Antonio for the Spanish localization!