If you have the "app not installed" error thing most of the time it means you don't have a lot of storage for your phone to be working so i suggest having like 2GB when you install games via apk's
well, it also depends on what type of apk it is. Some are made of windows, the other for mac, etc. Just make sure you have the right apk, and the right amount of space on your phone, and it should work. 😄
