As you won't be publishing the app you can decide for yourself how up-to-date you want to be
The usual warnings apply
1) about all apps built with Xvversions, do not attempt to upload your app to Google Play
2) about launchers, make absolutely sure you have left yourself a way out of your launcher until you have completely finished testing it
and preferably have a way to install a standard launcher in its place even when you have fully tested
If you lock your phone and have no way out but a hard reset wiping your phone, we can't help you