Green display

The green display application keeps it simple!
Suppose your settings (configurable from the application user interface) are as follows:

Then

Application states

The following icons are visible in the status bar icon on the left and represent the Green Display status:

Disabling the proximity detection is not a good idea in general, because if you forget to turn the screen off before placing the device back in your pocket then the display may remain active for an undetermined period of time.
That said, disabling the proximity detection in landscape mode can be a good choice to avoid the screen going off while reading in landscape mode. At the same time it is not so dangerous unless you put the device back in your pocket (or handbag) horizontally forgetting to turn the display off, the combination of the two being hopefully unlikely!