I haven't thought about the license before.
It would be something like: leave a credit, do not sell .

I don't want to release the source code because I'm going to monetize it on other platforms except Fremantle and Harmattan ( eg. Ubuntu ).

about extras-devel...
I received an invitation yesterday, I tried to upload it but I failed at "upload .changes file" step. I tried to generate it with dh_genchanges but I also had problems at creating proper "debian/changelog" file.

I would appreciate any help but if you could upload it, I have nothing against this.