mCent is an app that lets you earn money by doing something as simple as downloading apps and testing them. As soon as you open one of these apps for the first time, you receive a small amount of money, and if you keep it for a week, you receive a little more.
To use mCent, you need a smartphone. You also need to be in one of the participating countries, such as the United States, Argentina, Mexico, Vietnam, Russia, Sri Lanka, etc.
One of the drawbacks of mCent is that the app monitors your use of the apps, and it can freely access your address book. Of course, the app notifies you before doing anything, but that doesn't make it any less invasive.
mCent is an interesting app you can use to earn some money by simply downloading and opening certain apps.