Here's some tips on using SmartFlybox.
SmartFlybox's Settings are changed using your device's “Settings” app. Open the "Settings" and scroll to where you see all your apps on your device listed alphabetically. Touch the SmartFlybox icon to change one of the following settings:
Once you're familiar with using the app, you can turn off my annoying “hints” here.
SmartFlybox works within a radius of about a finger-width to locate flies. If you find this is too wide and you're unable to select a particular fly in the box, then slide the slider left to decrease the size of the radius that SmartFlybox looks in.
If you find that you're not able to locate flies, then try increasing the size of the radius that SmartFlybox uses by sliding the slider to the right.
Sliding the slider to the approximate center reverts back to the default of about a finger's width.