Discord History Tracker - Discord History Tracker is a great tool that enables you to select chat history and save it in your private conversations, servers, groups, and then view it anytime without needing an internet connection.

Shtuff Chat - Free Group / Team chat with persistent history.

Pyno - Pyno is a mobile application that shows your Facebook chat history.

Anologue - Disposable online chat.

iMessage - iMessage is an unlimited text messaging system for the Mac OS X operating systems that provide the iOS users to send unlimited messages to other iMessage users on Mac or other iDevices for free.

Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.