[orthecreedence]

There's no excuse not to open source an app if it's privacy oriented. It's not enough to open source the part that does the crypto either, because how do you know it isn't accidentally logging plaintext data to a file somewhere before the crypto happens?

There are other ways to do lock-in besides closed-source clients. If it has "private" or "crypto" anywhere in the title, it needs to be open source.