You can't actually mine ETN on your smartphone. It's kind of like a simulator but you do get ETN when you "mine" using the ETN app.
I personally like ETN, keeps me constantly updated on its development through email and has an android/iphone app of it's own.
I hope it works out great and able to penetrate more trading platform like binance
Crypto has already developed many new ways that can help us earn passive income. Mining, as you have stated, is only one way. =-)