Today most mobile operating systems provide an application portal (e.g. Android Market, A ppStore) where users can search by ke ywords and e xplicitly rate applications published by third-party developers. In this paper we go be yond this approach and introduce an implicit rating mechanism for Android programs. Our a pproach, c aptures installation, upd ate, a nd removal e vents, a nd allows to show them a mong us ers. B ased on these m easurements w e cal culate i mplicit ratings. As a result we compare these ratings with explicit ratings from the Android Market. For applications with less than 5,000 downloads implicit ratings provide more information than users explicitly enter on Android Market.