Just like what other members say there's no way that you could actually mine on a smartphone on an application because it just doesn't have mining power or hardware that could possibly mine Bitcoin or even other altcoins, I mean there are somewhere you could mine using your pc back in the day I can mine some altcoins using my pc on some website I can sell them on the market but it just wasn't worth that much and considering it's going to use your GPU it just wasn't worth it the way I see it.

There are some popular mining that gets trendy in the past months I think, Pi network I think where you can mine them on your smartphone but it turns out to be fake, you just need to open the application and it would start to mine already but it was just numbers and UI where you see the numbers increasing thinking that your phone is actually mining, but they just do it to get peoples information since you need to register and have an account on the application. The way I see it is developers of this Pi network are actually legitimate, but thinking that the coins you mine on your smartphone would get a value is very low. I mean if it did it would still not even be worth it because of its supply.