[tnova]

As opposed to the two you mentioned, WhatsApp has e2e by default. Kakaotalk and Telegram force you to use "secret chats" for that which are device to device only and cannot be shared among different devices with the same account.

[BubuIIC]

Uh, well, both WhatsApp and Signal are single device only to begin with.

[oarsinsync]

I can continue an encrypted chat in Signal from my desktop. I don't think I can do that in Telegram.

[fouc]

Do you need a password to do that?

[baby]

Nope, scan a QR code