GB App is the most popular instant messaging app with more than 2 million downloads in the Google Play Store. It's a free and easy-to-use messaging app that allows you to send and receive text messages, video and voice calls, and even make group chats.

There are several ways to get started. If you are a regular user, you can download the app and use it without any extra settings. If you are a new user, you need to set up your phone number. In either case, you need to provide your phone number and an OTP to get started.

Once you are logged in, you can send and receive messages, video calls, voice calls, and even group chats. You can also add your contacts to your phonebook and send them messages. You can send and receive messages and video calls from your contacts and group them by contact or category.

You can also save your messages, video calls, voice calls, and even group chats in your phonebook and access them later. If you are the group owner, you can also manage your contacts, messages, video calls, voice calls, and even group chats.