A simple add-on needs a simple license, essentially:
- Use of the code in commercial projects is allowed and encouraged!
- Redistribution of the source code is NOT PERMITTED!
- Any add-on code changes you make or add belongs to you and does not need to be committed back to the project.
- One (1) license allows for use by small teams of 3 people (seats) or fewer. Any more than 3 users contact me.