I'm building an End-to-End-Encryption app for Discord private chat, called discryptor.io [0]. It uses a Discord bot to deliver encrypted messages between users, rather than directly using the unprotected Discord chat.
I created an MVP for Windows but unfortunately haven't had the time and resources to make a mobile app yet. I would love to hear not just feedback on the execution, but the idea itself.
Also I'm not sure how monetizable the idea is but I'd like to give it a shot.