When posting here, avoid links (I did not edit that) and name your app so others can check it out.
http://www.techrepublic.com/blog/software-engineer/app-store-fees-percentages-and-payouts-what-developers-need-to-know/ broaches the subject of how much of the sale goes to the store.
I can't find the article but a top 10 software in the Apple Store (OS X, not iOS) made the author under 100 bucks. That's a sad story.
Have just launched an app ($0.99) with all proceeds going to charity. Do you think we need to mention this in the app? I really think mentioning #charity may worsen the app, because people may think it is just for publicity. What do you think?
Note: unnecessary link to app removed by moderator.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic