extend the basic Android permission system to allow users to specify conditions under
which an application is given permission to access the spec-ified resources. For example, using
Apex a user can specify that his application can only access GPS location when country is United Kingdom"
at installation time. Without Apex, users can only grant the access to GPS Locations
without differentiate the contexts. Our premise for all scenarios cited in this paper is that Apex is already used to
manage permissions over resources.