Of course making money is one thing, but those with ads and all those pop ups, well you better be very careful with just installing random apps. At least now many of them tell you they have ads before you install them, at least on android which is more than you would like. You can now get who knows what from ads not to mention your battery getting drained because those same apps won't let your phone sleep. Even if they don't have ads, you still need to check what rights they want or have. For example, why would a notepad app need camera access or why would a flashlight app need the camera and mic for?