Especially in the light of Zuckerberg's recent behaviour, please consider using Signal, it's actually good and a pretty easy replacement for Whatsapp

https://signal.org

Signal Messenger: Speak Freely

Say "hello" to a different messaging experience. An unexpected focus on privacy, combined with all of the features you expect.

Signal Messenger
@joelanman if you don't like sharing your phone's number or don't have a phone or a number, consider using #matrix. Some universities already offer matrix servers! It's decentralized, similar as email: choose your provider(s) of trust, choose your favorite client(s).
@ff7 @joelanman Or just use #XMPP #Jabber with #OMEMO on which most of the other stuff is technically based anyway. And it is federated, which Signal is not. And there are beautiful apps like @Monal and #Conversations by @daniel