Calldorado ApS is an innovator in mobile app monetization, providing a solution that drives the commercial success of Android apps. Using the Calldorado Caller ID SDK, app owners can generate revenues even when their app is inactive and at the same time re-engage users. Once the easily integrated Caller ID SDK has been added to an app, the Calldorado platform serves ads to the Caller ID screen at the end of a call, while space on the same screen provides app owners with an unobtrusive hook for re-engagement. Caller ID reveals the identity of a caller even if they are not in the user’s contacts. Calldorado’s solution addresses both monetization and user-engagement – two major problems in the increasingly crowded Android app market.