Hi @cmeredith - I was able to launch the twitter app on my Android phone by calling Linking.openURL('twitter://user?user_id=55679782'). I think you need to provide some additional content to the URL rather than just trying to open 'twitter://'.
If that doesn’t solve your problem, could you provide a snack that reproduces it?
@cmeredith - glad that worked! I agree, that is weird we try to abstract away as much odd platform-specific behavior as we can, but we don’t have much control here sadly!