I confess to having bought the feature that lets you move frog eggs out of the nursery into one of your other habitats in Pocket Frogs. And I think I might have bought either a packet of stamps or potions once during the early rounds. The stamps or potion buy was a complete cave-in to impatience, but the other thing seemed reasonable because it's such an impediment to have to wait for high-value eggs to hatch, especially if you have plenty room in the other habitats. I didn't really mind paying for it. If you play the game on another device, that ability to transfer eggs is one of the purchases that you don't have to buy again. Stamps and potions don't work that way, however. Makes sense but anyway I never bought stamps and potions again. Patience became my tactic. I don't have any other games with in-app purchases. I can see how parents could find them extremely annoying.