Telegram, Signal, Facebook Messenger, Threema, Torchat, Tox, ChatStep, Zulip, Burn Note, XMPP, Simple SMS Messenger, Conversations, SureSpot, Element X, Cryptocat, Talkonaut, Psi+, Otr.to, BitMail, SimpleX Chat, CoyIM, Sicher, SumRando Messenger, Jabbin, yaxim, Speak Messenger, GoldBug, Hemlis, Bopup Messenger, MetroIRC, Pidgin-Encryption, HWIZIT, Numbertank, Psyced, MyENIGMA, Speeqe, PrivyTalks are some alternatives to ChatSecure.