If need be, it’s possible for you to also leave agroup text.
GroupMe
Clean interface
Calendar tool with reminders and attendance.
Easily handles groups of 2-75 members.

Supports the circulation of photos
The left navigation bar can feel cluttered.
The buzzing smartphone can become irritating.
No shared document authoring ability.

Does not handle multiple one-on-one conversations well.
GroupMeis an excellent tool because it is so easy to get started.
The calendaring, desktop interface and photo-sharing are all accommodating in GroupMe.

Backed by Facebook.
Supports photos and videos
No desktop interface.
Cumbersome to create new groups
Limited file size.

It is also a tool that does charge a small fee for yearly subscription use.
Slack is a nice-looking group messaging tool that fits somewhere between a casual group and a professional project team.
Shared documenting is helpful for some groups.