Great app until it crashes – Math Planet - Fun math game curriculum for kids Review

My kids love to play this and it's such a great way for them to sharpen their math skills, but..... it crashes! Once my son got to a certain level he couldn't go any further. Crashes every time. I payed way too much for this kind of poor quality. I even wrote to the company asking if they could fix the glitch or give my money back but they didn't respond.
Review by New phone for Christmas on Math Planet - Fun math game curriculum for kids.