Hey!
These lens flares were originally were created by Prete aka Priest and he gave his permission to use the code for free in any project (free/commercial), just don't forget to give him a creadit. But that goes only for the code, not resources. So in order to use this for commercial projects, you need to create your own lens flare sprites
There is a CREDITS on my github about these lens flares:
https://github.com/3RUN/Lens-Flare/blob/master/CREDITSAs for me, I would be happy if any of my work is useful, it doesn't matter in which ways (free/commercial). No need to give me credit too
Best regards!
