Pocket Frogs

VIP (the most expensive item) is at the top of the shop, and the next item is one of the cheapest.

Taming frogs (allowing them to be bred, traded, or used in games) requires hopping from one lilypad to another eating dragonflies. The higher level the frog is, the more dragonflies it needs before it becomes tame.

Each habitat can only hold so many frogs, and you can only buy so many habitats without making a purchase. You can only have eight items in your mailbox without making a purchase.

Having an account with VIP status is more valuable.

VIP sales occur somewhat sporadically. The shops' stocks also change daily.

Free rewards are granted every two hours.

Frogs have an arbitrary amount of time it takes to hatch. The timer can be reduced using in-game items.

You can give frogs and items to other players.

You can buy potions to speed up frog egg hatching times, and reduce taming requirements. You can also buy stamps, which let your mailbox deliveries arrive faster.

Higher level frogs require more potions, and higher level items or frogs require more stamps to speed up mailing times.