Telegram also supports proper E2E in the form of secret chats, though the UX is definitely not as good (for example, last I checked it did not support group chat or multi device.)
EDIT: Was under the impression Telegram served closed source clients. Turns out it does not. I stand corrected.
OLD COMMENT:
E2e using a client that is not opensource (on a system that is not trusted) is not helping much.
E2e where the server is not open source should be okay, because the server-end can only snoop on some meta data (how much, when, what IP, chunk sizes, etc.) but not the content.
OLD COMMENT:
E2e using a client that is not opensource (on a system that is not trusted) is not helping much.
E2e where the server is not open source should be okay, because the server-end can only snoop on some meta data (how much, when, what IP, chunk sizes, etc.) but not the content.