First, download the png images from the first post. Open OPFP Control app then click the option (Icon Image Normal) to select the image then do the same for Icon Image Disabled. If your app force closes then clear the Storage & Cache of the app. You are good to go...
Cleared storage & cache. Also, tried uninstall & re-install.
Unfortunately same problem: I get "OPFPcontrol keeps stopping" FC.