I actually used a home-made framework that I have been kludging together since my first app, BridgeBasher. Back then, Cocos2D and Unity3D weren't as awesome as they are today. It worked out well though, having my own framework really lets me dig into the nuts and bolts and change any aspect that I need.
I have an email list of about 80k subscribers that I've accumulated from my other apps. About 28% have opened, and about 25% of those who opened actually clicked the link.
Yesterday I clocked 3879 downloads and landed at #52 in the charts. I'm not sure how many downloads I've gotten today.
I decided on the $0.99 price point because of the large e-mail list.