GroupMe

GroupMe is a totally free application, that lets you communicate easily through text messages with any friend, regardless of the type of device or cell phone that they have. In fact, the application even works with tablets, since it uses your data connection (or WiFi) to send and receive all messages.

You can start up new interesting conversations directly with friends, and you'll also be able to create and participate in group conversations since it is easy to sync to a work group, or keep yourself up-to-date with the goings-on of your friends.

One of the interesting concepts of the application is that whenever the internet connection isn't very good, it can start receiving messages using the SMS system of your phone, so that you don't lose even a single message.

GroupMe is an excellent instant messaging tool that, like other similar apps, lets you sent photos, videos, and other files using the chat system, as well as receiving notifications to be up-to-date.