You have to improve your enjoyment of learning, not just with your mobile phone. If you don't play with a mobile phone, you will be attracted to other things because you don't want to learn.
And if you want to use your mobile phone, create a schedule or use a scheduler. In following that, you will have to discipline yourself and you only use your phone if its needed.
Using phone when you have other important things to do will distract you and will remove your focus.