Hello everyone,
Do you want to mining crypto currency coins?
I think to use some old android mobile to mining coins (XMR is the best Opinion now).
1 Mobile with 10 H/s and you can earn = 0.000186 XMR per day
10 Mobile you can earn 0.00186 per day
100 Mobile you can earn 0.0186 XMR per day
Buying old and cheaper Mobiles on markets and do it in free time...
You can use Android App here
https://minergate.com/a/39cc23b093a54ee8b6e4d303