For now mining on mobile phones are not worth it. Yes you can still earn and mining is possible but using your expensive phone just to mine a few coins is not worth the risk. But if you are one of those youtubers who gets a free phone to review each time a new phone comes out in the market, I could say I would give it a shot. Since the the device costs is $0 as it is given for free to review then earn a few dollars from it being idle. But since crypto currencies are booming now, I should say that those phone companies are already looking to innovate their phones in order to mine coins. I saw samsung lately trying out to mine coins using a bunch of galaxy S5, so I guess samsung or other companies are already looking at a possibility to create a phone that would be profitable at mining. It might not be this year but we should see some new technologies in the coming years and this could be on of the breakthroughs of mobile mining.