You can go to www.lumosity.com. This is a website put together by neuroscientists. It has lots of interesting games you can play that increase your brain power. You can tell it what you want to improve (attention and focus, for you), and it will give you games that will help your brain get better at these things. I use it for the same reason, and it's really helping me. You can go to the site every day or every other day, as often as you want, and it will send you email reminders on those days to come and play. It's very cool.
The best way you can focus better is to set goals so as to give yourself a challenge. You need to right down things that you want to achieve or accomplish with anything that you plan to do. You also need to look at the best part of getting something done like the outcome of benefits as this can help you stay focused too.