If you really feel the need for a cut down version of Lanterne you could call it Torchio
If you feel it's useful you could add an option to lock the screen too on lens close/application close
The only final comment I have is your preferences windows (all pasta shapes) seems to be a few pixels too big for portrait operation.
I like pasta, hopefully we will see many more varieties. I am sure there are many more simple but much needed applications.