iTunes is one of the most popular tool to find and download apps for iPad or any apple device. Zoom Appy is another example which gives you visual map of the Apple App store and includes filtering criteria such as price, device, connectivity,paid or free, what features of the phone is used. The search result is an awesome visual map where each one can be zoomed and information can be seen so you can search for the latest and most popular iPhone and iPad apps.
Another great feature of this tools is that when you view information of the single application, clicking on any of the information e.g. Price 0.99 will filter the and show all the apps which are of 0.99 price range.
Though Zoom Appy have only Apple App store games now but it seems that they will include the Andrioid and the Windows Market Place Also. Check out Zoom Appy