I'm in a similar position, so I have blown the dust off my Nintendo DS and bought Brain training for 50p at a local shop. You can get the Math focused version "Math training" too.
The games track your progress well and adapt to your skill level. It is away from your connected devices so reduces your chance of getting distracted. Also it's a beautifully designed game.
The games track your progress well and adapt to your skill level. It is away from your connected devices so reduces your chance of getting distracted. Also it's a beautifully designed game.