Wispi is described as 'Get Wispi and connect to the world freely!' and is an app in the Social & Communications category. There are more than 100 alternatives to Wispi for a variety of platforms, including Android, iPhone, Android Tablet, Windows and iPad. The best alternative is Telegram, which is free. Other great apps like Wispi are Signal (Free, Open Source), Element (Free Personal, Open Source), Jitsi (Free, Open Source) and Skype (Freemium).
With Viber, everyone in the world can connect. Freely. More than 460 million Viber users text, make HD-quality phone and video calls, and send photo and video messages worldwide over WiFi or 3G - for free.
Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG]. [Note] **You can download the compiled apk for free from F-Droid**: ...
An open-source decentralized and encrypted messaging app even without internet connection via Wi-Fi and Bluetooth. Messages are stored securely on your device, not in the cloud. Connect directly with nearby contacts - no Internet access is required.
Franz is a free messaging app / former Emperor of Austria and combines chat & messaging services into one application. Franz currently supports Slack, WhatsApp, WeChat, HipChat and many more. You can download Franz for Mac, Windows & Linux.