Android - Black screen starting an app
Black is the default plot color for Android, so this is the placeholder until the app completes it's layout operation. There are a number of things that can cause an app to have a delay here:
- Performing a network call(s).
- Loading data from disk.
- Garbage collection from other tasks.
- Restoring a complex drawing.
You can check to see if it is related to network latency by putting your phone in airplane mode and opening the app. If the app pops right up, the long delay is likely due to a network call that takes a while to complete (and completes immediately as an error when there is no connection).
The other three are trickier to test for. If it is garbage collection, you will likely only see the delay when other apps have been recently running and then switching immediately the misbehaving app. You can completely uninstall an app, including user data, and then re-install to see if it has something to do with your personal settings.