This app is full of hackers and scammers. Bitcoin scams are very common. Even after I put a passcode I still got hacked twice. Your conversations can be seen by telegram UNLESS you make them private. Telegram stores conversations on their server, so if it gets hacked, all of your private conversations are hacked. On whatsapp your conversations are end to end encrypted so no one can see them even whatsapp. I never got hacked on whatsapp only on telegram.