Reaper is a free to play action RPG that has in app purchases including one for a full game unlock for $4.99.
Pro Playable in small chunks
Mobile games are great for playing for just a new minutes here and there, and Reaper works exactly like that. If you've only got 5 minutes, you can still enjoy it. Some mobile RPGs need plenty of time to get into the mood and enjoy, which isn't always possible on mobile.
Con Free gameplay is limited to ten levels
The gameplay is free up to the tenth level, at that point an in app purchase has to be made of which there are three depending on how much content you want. $3 unlocks the rest of the levels, while $4 nets you more in-game items, and $5 gets you everything available as well as the Dark Harvest game mode.