Android: Putting A Custom Permission On The Main Activity - Bad Practice?

I have a simple application that runs a webview and I want it to be launchable by other applications sending a few parameters that I will include in the URL string. To accomplish t

Solution 1:

should I never put a custom signature level permission on the main (launchable) activity of the application?

Yes, unless you are the author of the home screen or other launcher and can ensure that it holds the custom permission. Otherwise, you may as well take off the MAIN/LAUNCHER<intent-filter>, as it is advertising something ("hey, launch me!") that is not generally true.