Even worse. The dev wrote somewhere that the mobile mining is just some kind of fake. Every holder of Electroneum which uses the mobile wallet will receive some coins over time automatically. So the app should not use much battery power or CPU of the mobile devices. This is just some kind of marketing to increase the number of users of the mobile app.
The real mining (support of the blockchain) will still be done by miners who use their PCs.
But it could work. If the greed for more free coins drives the masses to use the app, all hodlers could profit long term once milliones of users download and use the mobile app.