WhatsApp, Talkatone, Tango, Viber, Whereby, aTalk, Zulip, Daily Co, BNESIM, mytello, Talk360, toolani, KeepCalling, Pinngle, Tinode, FooCall, Sesame Chat, Spaxtel, Localphone, mene talk, letsBrik, FriendCaller, Amivox are some alternatives to RebTel.