When comparing Line vs GroupMe, the Slant community recommends GroupMe for most people. In the question“What are the best messaging apps for Android?” GroupMe is ranked 23rd while Line is ranked 29th. The most important reason people chose GroupMe is:
GroupMe has a built in function to read receipts.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Large celebrity and public figure usage rate
The caveat is that they are in Japan, but the app is commonly used to 'follow' public figures.
Pro Enormous, constantly updated stamp collection
Since many brands use stamps for promotional purposes, everything from movies to food brands to Taylor Swift have released stamp collections.
Pro Photo filter and editing capabilities
Users have in-app editing tools, as well as Line's separate camera application, which has additional tools.
Pro Integrated social network
Similar to Facebook's timeline.

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.
Cons
Con Account is locked to the Phone Number & Device
The entire account is locked to the phone number, which cannot be changed. If the application is installed on a new device with the same phone number, the previous account data will be wiped.
Con Users have been concentrated in Japan
Of the 360+ million registered users, the top country is Japan (50 million). Thailand and Indonesia are 2nd and 3rd with 33 and 30 million, respectively, with very small market penetration in the US (10 million, 11th place).
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.
