In a future XnView mobile app...
It would be nice if in future the "Spotlight" feature could be considered for a mobile version.
Not n important feature but still can come in use especially for smartphone photo Screenshot editing as well as maybe some live presentational use with "spotlight" on images (smartphones like Iphone/Android devices can plug into external larger displays).
Just imagine it:

With some 'PowerAMP' style settings knobs to make configuring the settings super efficient (quick) on a mobile GUI: