Idk but i found it on my facebook home, he just use unused tab for mine.. and it's free he said
Yes, it's monero, altcoin mining. But the risk to break your phone due to over heat and push the cpu, it's not worth.
People can't mine bitcoin easily through CPU, GPU, browser phone or tablet as it's not profitable and not worth at all compare to the risk, you need real hardware such as antminer s9 to mining bitcoin. Just simply like that.