I wrote some usefull missed scripts based on the UFPS framework.
I have seen other package on sale that includes only scripts for NGUI or Playmaker etc (from different authors)…
I know that I can include in the package only the new scripts and not the original package… but Can I sell my scripts? Or I should ask to UPS authors the permission?
Assuming that you have written all the code in the files, there is no legal problem that I can think of. Even if there is a problem, the asset store team will probably bounce it so you’re covered either way.
If anything, it is good for the author of the original package if people develop things around his package as it will increase functionality and possibly bring in more sales for him.