When comparing GroupMe vs Echofin, the Slant community recommends Echofin for most people. In the question“What is the best team chat software?” Echofin is ranked 21st while GroupMe is ranked 49th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Reads receipts
GroupMe has a built in function to read receipts.

Pro Great web client
GroupMe has an excellent web client that can be used to send and receive messages and manage groups from the desktop.

Pro IFTTT Integration
Allows sending messages from web services via IFTTT.

Pro Integrated calendar
It's possible to add location and time with reminders directly in the GroupMe app.

Pro Makes it easy to silence 1 or all groups
GroupMe has settings that allow muting a single group or turn off all GroupMe notifications from within the app.

Pro Does not require everyone in the group to have a smartphone
GroupMe can set up a custom phone number which allows people without the App to send and receive messages. This makes it easy to add anyone to messaging.
Pro Beautiful UI
Pro Powerful financial widgets
In-app widgets, such as an economic event calendar and news feed, are available.
Pro HD video streaming
Pro Mobile, web and desktop apps
Pro Ability to add pay-to-access content
You can host pay-to-access webinars.
Pro Integrated billing solution
Pro Screen sharing
Pro Chat software specifically for trading teams
Pro Talking twitter widget
Pro Admins have full moderation and user control
Pro Third-party integrations
For example, you can integrate the app with your MT4 web client.
Cons
Con Drains battery fast
GroupMe, in order to have a constant connection which allows for notifications drains the battery of a device quickly, which is not ideal for a messaging app that one needs on time notifications from.
Con Cannot customize UI (i.e colors)
Con Relatively new
Con Currently only available in English
