Released in May 2010, and later purchased by Microsoft, GroupMe is a free-to-use chat app available for download on iOS and Android smartphones. It is also available as a web application, accessible using a supported Internet browser. GroupMe allows users to create group conversations by searching for others by name or phone number, or by inviting existing contacts to the service. Along with simple text-based chat, GroupMe supports images, videos, location sharing, and custom emojis.
All that is required to sign up for GroupMe is a phone number.