The growth of Japanese social networking app Line since it was...

The growth of Japanese social networking app Line since it was launched in June 2011 will be useful to contrast and compare to the Migme in the coming months.

http://en.wikipedia.org/wiki/Line_(application)

It now claims 170 million MAU and wide acceptance throughout Asia.

As I read it the fundamental difference to Migme is that its used on high-end smartphones rather than the low priced devices selling for about $45 targeted by Migme.  Others may be able to correct me on that assessment.