Android has a few really good settings built right into the platform for debugging under a hidden “Developer Options” menu. You can turn then on via Settings -> About Phone -> Build Number (tap 7 times). The steps will be similar but might vary a bit across OEMs. In older versions of Android, this used to be an explicit option under the Settings tab.
I find the following options to be useful for the development
- Don’t keep activities
Android can destroy any activity which is not visible in the foreground at all. The destroy is a bit of a misnomer here since activity will be allowed to preserve its state (via saveInstanceState). This option allows you force that on all apps. It is harder to keep this option always on since many badly designed Android apps misbehave and even the good ones have a deteriorated performance due to repeated re-creation. I wish there was a way to force this only on the app under development.
- Force RTL layout direction
to test your app’s look & feel in an RTL language like Hebrew or Urdu. This option is useful since it actually reveals evolving and varied behavior across different versions of Android
- Profile GPU rendering
Shows a nice cool graph of the load on the UI thread and when your app fails to render a frame in Android recommended 16 milli-seconds timeframe.
- Stay awake [while charging]
when you don’t want your screen to turn off while it’s charging [& connected to your laptop for the development]. I wish Google actually provided “Stay awake while USB debugging” option.
- Verify apps over USB
Disable it unless you don’t trust the app you are working on
- Pointer Location
This option draws a set of perpendicular lines at the point of touch, useful to see if a set of views (like buttons, text fields etc.) align or not.
- Show Layout bounds
shows the bounds of all the views, annoying to always keep on but useful for quick testing.
- Debug GPU overdraw
Google recommends it but I have rarely seen any benefits of turning this on since due to animation, overdraw is almost always present.
- Running services
You can check out your app and see if it is listed and is running some spurious service in the background.