LOL!!
That $250B market is one of products being sold, business to customer, and to use that figure is any sort of % math for an app is an exaggeration (being kind) of monstrous proportions. It is all over the OTC, of course, where a huge figure of a market sector is tossed up with the "whatif" of capturing some seemingly reasonable percentage of it, but it never ever works out, and mainly because the exaggeration is way better than whatever the product is (in this case, the apps).