At the moment we have two extremes of app store to choose from. On the one hand we have the Apple App Store with a lot of rules to follow before your app can go live. On the other hand we have the Android Market which is very open. In both cases the price your app sells for is up to the developer to set.Amazon is set to launch its own Android App Store in the near future. The company understandably seems to be taking a very hands-on approach to controlling what is available there so as to ensure quality. But it also seems to want to control the price of every app.If you submit your app for the Amazon store you can suggest a price for it to sell at. There is no guarantee the app will appear for sale at that price, though. Amazon will ultimately decide. The developer is protected to a certain extent, as Amazon will either offer 70% of the final price it chooses, or 20% of the price you as the developer originally submitted as the desired price.As an example, say you submit an app and want the price to be $5. Amazon decides to sell your app for $3 instead. You get $2.10 per sale rather than the $3.50 if the app was sold at your desired $5 price point. However, if Amazon decide to offer your app in a sale for $1 (or for free), the 20% desired price rule kicks in and you get $1 per sale rather than the 70 cents expected.When setting the desired price you want your app to sell for there seems to be only one rule: don’t set it higher than the price your app is sold for elsewhere. However, there’s no guarantee Amazon will choose your price just because it already sells on other app stores for that amount. As a business it makes sense for Amazon to undercut the competition on price.Read more at Business InsiderMatthew’s OpinionIt sounds complicated and as if the developer is losing control of their app to some extent. But it may turn out to that the developer makes more money from their apps this way.One thing Amazon is very good at is pricing items cheaper than anywhere else or having sale offers that move a lot of stock. If it does the same with apps then a surge in sales of a given app for a few days may earn more revenue for the developer than their desired price point would have over the course of a month without promotion. The other thing to consider is having your app listed on Amazon may be worth a lower price due to the number of customers that use and trust Amazon for purchases every day.As Business Insider rightly points out, having the price of your app set by someone else may be a problem if you sell across multiple app stores. Amazon could ultimately price your app lower than the competition potentially hurting your sales elsewhere. Will this stop developers signing up to list on Amazon?