Stopping an Android app from console

Solution 1:

The clean way of stopping the app is:

adb shell am force-stop com.my.app.id

This way you don't have to figure out the process ID.

Solution 2:

Edit: Long after I wrote this post and it was accepted as the answer, the am force-stop command was implemented by the Android team, as mentioned in this answer.

Alternatively: Rather than just stopping the app, since you mention wanting a "clean slate" for each test run, you can use adb shell pm clear com.my.app.package, which will stop the app process and clear out all the stored data for that app.

If you're on Linux:
adb shell ps | grep com.myapp | awk '{print $2}' | xargs adb shell kill

That will only work for devices/emulators where you have root immediately upon running a shell. That can probably be refined slightly to call su beforehand.

Otherwise, you can do (manually, or I suppose scripted):
pc $ adb -d shell
android $ su
android # ps
android # kill <process id from ps output>

Solution 3:

First, put the app into the background (press the device's home button)

Then....in a terminal....

adb shell am kill com.your.package