Monitoring mobile device usage

1. A method for determining user interaction with applications on a mobile device, the method comprising:

recording a first image of a mobile device screen at a first time, the first image including a first area with an icon that represents an application installed on the mobile device;

recording a second image of the mobile device screen at a second time that is after the first time, the second image including a second area with the icon that represents the application installed on the mobile device, the second area being the same as the first area in the mobile device screen;

recording a third image of the mobile device screen at a third time that is after the second time;

detecting a change in brightness between the first area and the second area by comparing pixels of the second area to pixels of the first area, the change in brightness resulting from a user selection of the icon to activate the application represented by the icon;

in response to detection of the change in brightness, determining an identifier of the application represented by the icon;

determining that the third image corresponds to a type of screen that is displayed when applications are no longer displayed on the mobile device; and

determining a duration that the application represented by the icon was displayed based on the difference between the third time and the second time.

2. The method of claim 1 , further comprising:

creating a first hash of the pixels in the first area of the first image; and

creating a second hash of the pixels in the second area of the second image.

3. The method of claim 1 , wherein determining the identifier of the application represented by the icon comprises determining machine-encoded text based on graphical text located at a defined position relative to the icon.

4. The method of claim 1 , further comprising:

recording a fourth image of the mobile device screen;

detecting a characteristic of a web browser in the fourth image; and

in response to detection of the characteristic of the web browser, determining a uniform resource locator corresponding to a web page displayed by the web browser.

5. The method of claim 4 , wherein determining the uniform resource locator corresponding to the web page displayed by the web browser comprises performing optical character recognition on graphical text located at a defined position relative to the characteristic of the web browser.

6. The method of claim 1 , further comprising:

recording a fourth image of the mobile device screen; and

detecting an advertisement visible on the mobile device in the fourth image.

7. A system for determining user interaction with applications on a mobile device, the system comprising at least one processor and at least one memory storing a software application that causes the mobile device or a collection server to:

record a first image of a mobile device screen at a first time, the first image including a first area with an icon that represents an application installed on the mobile device;

record a second image of the mobile device screen at a second time that is after the first time, the second image including a second area with the icon that represents the application installed on the mobile device, the second area being the same as the first area in the mobile device screen;

record a third image of the mobile device screen at a third time that is after the second time;

detect a change in brightness between the first area and the second area by comparing pixels of the second area to pixels of the first area, the change in brightness resulting from a user selection of the icon to activate the application represented by the icon;

in response to detection of the change in brightness, determine an identifier of the application represented by the icon;

determine that the third image corresponds to a type of screen that is displayed when applications are no longer displayed on the mobile device; and

determine a duration that the application represented by the icon was displayed based on the difference between the third time and the second time.

8. The system of claim 7 , wherein the software application causes the mobile device to:

create a first hash of the pixels in the first area of the first image; and

create a second hash of the pixels in the second area of the second image.

9. The system of claim 7 , wherein to determine the identifier of the application represented by the icon, the software application causes the mobile device to determine machine-encoded text based on graphical text located at a defined position relative to the icon.

10. The system of claim 7 , wherein the software application causes the mobile device to:

record a fourth image of the mobile device screen;

detect a characteristic of a web browser in the fourth image; and

in response to detection of the characteristic of the web browser, determine a uniform resource locator corresponding to a web page displayed by the web browser.

11. The system of claim 10 , wherein to determine the uniform resource locator corresponding to the web page displayed by the web browser, the software application causes the mobile device to perform optical character recognition on graphical text located at a defined position relative to the characteristic of the web browser.

12. The system of claim 7 , wherein the software application causes the mobile device to:

record a fourth image of the mobile device screen; and

detect an advertisement visible on the mobile device in the fourth image.