This concept has always existed, and you can compare it to e.g. steam credits. People found ways in the past to trade "virtual money" for real money, and this will be no different. The fact that it's a cryptocurrency adds a layer of transparency on top of it, and it looks like they're using it as an excuse to add additional value to their coin.

In reality, though, market forces will probably figure this out, and if it's not practical to trade for "real" money, it will not be worth much to app developers.