App analytics specialist SearchMan has created a new tool that aims to answer the fundamental question of “‘how discoverable is my app inside App Store search?”.

The new Search Visibility Score is based on the estimated volume of each app’s keywords, multiplied by an accessibility factor corresponding to those keywords’ search rank. The formula to calculate this accessibility factor differs according to the screen size of a device.

For  example, for an iPhone running iOS 6, with one search result per page, SearchMan assumes that each ranking position is only 90% as accessible as the position above it; for an iPad, with six accessible apps on every search result page, SearchMan assumes that each search result page is only 90% as accessible as the page the preceded it.

SearchMan CEO Niren Hiro told TechCrunch, “Everyone asked us for a simple uber-metric to answer the basic question of ‘how discoverable is my app inside App Store search?’… We have started to get requests from VCs, market researchers, and mobile ad networks who want to see more data about ‘momentum players’ who are achieving strong, organic, search-driven growth without giant ad spending.”

The new score appears under Market Data on the SearchMan site.