Yes, it is not authorized by bitcointalk, so it is very unsafe.
When you enter your login password, it may log your data. I don't think we should try an app like this，its creator is also a newbie with only 2 posts, which is even more unreliable.
Logging into the website of bitcointalk.org on your mobile browser is not difficult, don't put your privacy at an unknown risk.
If anyone is interested in this app, it is best to register a new account to test it.