Have you looked at Calculords? It's a similar type of game with an interesting IAP strategy of offering additional content. https://play.google.com/store/apps

Have you looked at Calculords? It's a similar type of game with an interesting IAP strategy of offering additional content. https://play.google.com/store/apps/details?id=com.ninjacrime.calculords https://play.google.com/store/apps/details?id=com.ninjacrime...