There's no way to mining via phone, phone processor is really low performance except you bought a high end phone that would cost you a lot. But it doesn't make sense to mine a cheap coins with expensive phone, you're wasting your money.
Theres a lot who did that in the past and not succeeded. Actually you got a point if the phone requires to mine such blockchain via phone then a stronger specs is very much needed. Well nothing cheap nowadays but even we buy a cheaper phone, likely the processing would be long unless the blockchain built is really design for that and well compacted in order to get mine.
OP can you name those two? That has potential to mine via phone which still survive up to now.