GroupMe is described as 'Group messaging platform owned by Microsoft. It's absolutely free, whether you're talking to a group of friends, or texting with one person. Best of all, it works on nearly every phone, via push or SMS. With GroupMe, it's easy to reach anyone, anytime, anywhere' and is an app in the Social & Communications category. There are more than 50 alternatives to GroupMe for a variety of platforms, including Android, iPhone, Android Tablet, Windows and Mac. The best alternative is Telegram, which is free. Other great apps like GroupMe are Signal (Free, Open Source), Element (Free Personal, Open Source), Tox (Free, Open Source) and WhatsApp (Free).
Signal is a messaging app with an unexpected focus on privacy, combined with all the features expected from a modern IM app. Signal has received a lot of praise from all around the world for its security and privacy-respecting technologies.
Element is a secure collaboration and messaging app based on the Matrix protocol. It’s decentralised to deliver digital sovereignty, and based on an open standard for easy connections and interoperability. It is end-to-end encrypted by default.
WhatsApp is an iPhone and Android messaging app which allows you to exchange messages without having to pay for SMS. In addition to basic messaging WhatsApp users can create groups, send each other unlimited images, video and audio media messages.
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.
LINE is a Japanese proprietary application for instant messaging on smartphones and PCs. Line users exchange text messages, graphics, video and audio media, make free VoIP calls, and hold free audio or video conferences.