Disclaimer I received these products for free for my honest opinion I would only recommend products that I truly love and would use myself.
My kids love anything they can use to make their brain work and they are loving these speed magic cubes by Inegear. These cubes are slightly flexible but are very similar to a Rubik's cube you have to get all the same colors in the same direction just like in a Rubiks cube. Speed magic speed cubes are 3 x 3 and come in a six pack these are great to keep for yourself or give some to your friends they would absolutely love them too. Even I sat down with the kids and tried to do this.