I will keep your coin under observation because using phones is very interesting and would have huge potential in future.
I am only afraid of too much wear, mining need some resources.. How about weaker phones and use rate new ones?
Have a read of this article - it explains the difference between our mobile mining experience and full mining and explains how we are going to take this to mass adoption.
http://financemagnates.com/thought-leadership/industry-poised-welcome-newest-cryptocurrency-electroneum/have a great day!
Richard