I use this everyday in homeschooling my son. I chose this app, because it is completely customizable. I can set it to specific problems not just +2s for example. If I want my son to work on 8+3, 9+5, and 4+2 for example, then I can select just those specific problems. It also shows how my son is at each of the problems, so I can eliminate the ones he has learned and leave the ones that needs more practice. The drill tells the child how fast the child went once the drill is completed. I use incentives to reach a certain mile per hour. With that, I have had my son begging me to let him do the drills over and over. The drill only shows one problem at a time, so my son does 60+ problems in one sitting without a complaint. It doesnt seem like that much work to him. If I hand him a worksheet with just 15 problems on it, he would shut down. Also, I emailed the maker of this app, and received a quick and friendly response. I recommend this app for homeschooling!