The phrase references the acquisition of an application, presumably designed for mobile devices running the Android operating system, that simulates or relates to a slot machine game, often featuring the number sequence “777.” Such downloads are generally offered without an initial monetary charge to the user.
The draw for users likely resides in the appeal of casino-style games on a readily accessible platform. These applications can offer entertainment and a simulated gambling experience without the direct financial risk associated with real-money gaming. Historically, the availability of such applications has been fueled by the increasing prevalence of mobile devices and the growth of the app market.