Because it is based on Twitter's Direct Messages feature, TwIM can be used to chat with any Twitter user through a search function that can locate people via name or username.
Messages are turned into in-line content previews with support for tweets, photos, GIFs, emoji, maps, and websites, plus the app has its own built-in face emojis called TwiMoji.
iPhone features like 3D Touch are supported, and the app includes built-in Siri functionality for sending messages through Apple's voice assistant. Push notifications for incoming messages are supported, as are rich notifications, and there's a useful share extension for quickly sharing text, photos, URLs, maps, and more from other apps.
For people who often use Twitter's DM feature to communicate with friends and family, TwIM is worth checking out.
TwIM can be downloaded from the App Store for free. [Direct Link]