Telegram is a messaging application that focuses on speed. It's simple, fast, and completely free.
Telegram allows you to create group chats up to 200 people, so you can keep in touch with everyone at the same time. You can also share videos up to 1GB and send multiple photos from the internet. Furthermore, you can forward any media you receive instantly. All your messages are stored in the cloud so you can access them from any device.
Telegram was created by developers to make messaging secure again, so you can regain your privacy rights.
You can download the iOS version here.