The stories you read are probably cloud mining which tells that we can mine bitcoin or it is a faucet type but that has a difference on mining btc. You need to have tool such as GPU and a power energy source to do this which I think phones can't probably cant supply unless someone integrate it on the mobile but that would be useless.

I heard this project Taucoin which is planning to build a mobile app mining and I guess they have potential to pulled it off using a different consensus protocol. But for btc not possible or never will using POW.