Chat-app is a chat application that allows users to participate in multiple chat rooms without any signup requirements. The app includes features such as the ability to create multiple chat rooms, support for a large number of users in each room, and the ability to use emojis in chat messages. One of the notable feature is that, it is secure as it doesn't store the messages on any servers, which means the chat logs would be lost if the user logs out the chat-app, all the messages would be stored in the device, where chat-app is running.