Hello, @starjewel, and thank you!

Yes, the free use is for articles on all dapps connected to steem blockchain, not only steemit.com, also busy, steempeak, fundition, etc.

You just have to source your images as normally required by the community - showing the source of the image - a link to its place in the gallery, the gallery itself, but also mentioning my account - something like

photo by @manoldonchev

counts.

If anybody would like a larger file for other use, they may contact me. Actually the awkward part is that the gallery has details in the description on the site, but it is when you go one step back in the archives - the cover of the gallery. Will talk to developers about that at some point.