Wire is described as 'is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption' and is a very popular Group Chat App in the Social & Communications category. There are more than 100 alternatives to Wire for a variety of platforms, including Android, iPhone, Online / Web-based, Windows and Mac. Most alternatives are Group , Video Calling App and Encrypted Chat App. The best alternative is Signal, which is both free and Open Source. Other great apps like Wire are Telegram (Free), Element (Freemium, Open Source), Discord (Freemium) and Jitsi Meet (Freemium, Open Source).
Technitium Bit Chat is a secure, peer-to-peer (p2p), open source instant messenger designed to provide end-to-end encryption. It can be used over Internet and private LAN networks for instant messaging and file transfer.
Nertivia is an chat client that allows you to chat to anyone across the world. There are a lot of features that don't require you to pay at all such as, gif profile pictures, free custom emojis and more coming soon!
Kopete is an instant messenger supporting AIM, ICQ, Jabber, Gadu-Gadu, Novell GroupWise Messenger, and more. It is designed to be a flexible and extensible multi-protocol system suitable for personal and enterprise use.