I'm the developer, so take this as self-promotion; one post, and I'll answer questions here.

What it does: messages, pictures, files and voice notes, plus voice and video calls, always one to one. There is no sign-up. You meet someone, scan their QR code (or open the link they send you), and that's the contact. There is no directory, so nobody can look you up.

Where things live: the conversation is stored on the two phones and nowhere else. When both phones are reachable, a message goes directly from one to the other, end-to-end encrypted. When the other phone is off, a mailbox on our server keeps the encrypted blob until it is collected, seven days at most; you can switch the mailbox off in Settings if you prefer messages to wait on your own phone.

Inside a chat there is an Apps tab: a document scanner, a shared list, a whiteboard you can draw on during a call, a translator that runs on the phone, and a few two-player games such as chess.

Known limits, so nobody is surprised: with a direct connection the other phone can see your public IP, and the wake-up push goes through Google (it carries no content). It only works if the other person also has it. iPhone is coming soon.

Play Store: https://play.google.com/store/apps/details?id=com.flickertalk.app Source (AGPL-3.0): https://github.com/FlickerTalk

I'd like to hear what was confusing the first time you opened it, and which tool or game you'd want next.