Multi-device support and message sync do not necessarily preclude end-to-end encryption. Of course, it's a lot easier to accomplish these without end-to-end encryption.
Wire [1] (which I discovered a few months ago) is a platform that has end-to-end encryption, multi-platform support and multi-device sync. It also has text chats, voice calls, video calls, doodling, etc. The UX still needs a lot of improvement (compared to Telegram).
Wire [1] (which I discovered a few months ago) is a platform that has end-to-end encryption, multi-platform support and multi-device sync. It also has text chats, voice calls, video calls, doodling, etc. The UX still needs a lot of improvement (compared to Telegram).
[1]: https://wire.com