May I use the "Skorpio's SciFi Sprite Pack" in an IOS app? It would be a commercial app, because of the ads and in app purchases.

How would you like to be credited? e.g. "Skorpio on OpenGameArt.Org" or would you like that your realname / other artist name is used?

Btw. Do you still have the XCF or PSD files for your designs?