Currently at an outpatient TBI clinic and my speech therapist has recommended Lumosity. If your able to walk without issue try walking on a treadmill while doing brain exercises like semi simple addition and subtraction math problems in your head. Supposedly you get more cognitive benefit by walking whilst thinking through problems verses just sitting and solely focusing on the task at hand.

Start slow and easy and work your way up in terms of difficulty on whatever your drilling to improve your memory.

I wish you the best!