Bash Android: Run gradle install flavour and send an intent to every device in order to launch application on all devices.

run.sh

#!/bin/bash
# Runs gradle task installGoogleDebug and starts MainActivity on each available running device and emulator.
./gradlew installGoogleDebug &&
adb devices | while read line
do
	if [ ! "$line" = "" ] && [ `echo $line | awk '{print $2}'` = "device" ]
	then
		device=`echo $line | awk '{print $1}'`
		echo "Starting Application on device: $device $@ ..."
		adb -s $device shell am start -n io.mazur.project/io.mazur.project.ui.MainActivity
	fi
done

Slight modification of:

http://stackoverflow.com/questions/8671819/how-can-i-use-adb-to-uninstall-an-apk-from-multiple-connected-devices