ADB (Android Debug Bridge)
Viewing connected devices
adb devices
Downloading and uploading files
adb push myfile.txt /sdcard/
adb pull /sdcard/myfile.txt
Installing and removing apps
adb install myapp.apk
adb uninstall my.package.name
Shell access
adb shell
Reinstalling a system app
adb shell pm install-existing com.google.android.gsf
adb shell pm install-existing com.google.android.gms