As discussed earlier in another thread, I've been working on some additional themes for the Themes Marketplace at themes.tiki.org that can be downloaded and installed for Tiki 15. My themes site is https://zukathemes.com and you can check out the information there or at the Themes Marketplace. The idea is that theme authors can have their themes listed at themes.tiki.org, which will function as a kind of informal registry. They can be downloaded from there (so file packages can be double-checked for safety), but they'll be demonstrated at the designer's site.
For now (actually the only plan considered so far), the themes are free and open source. Of course if anyone wants to offer premium (not free) themes, that's great, too. The payment would be handled at the designer's site also.
Anyway, so far I've done four themes (one has five theme options) that are adaptations for Tiki of themes for other software or HTML templates. Please download and try these out if you like. There are quite a few more in the pipeline and they'll be coming out maybe one or two per week.
I think something valuable about this is even if no theme is a perfect match for a site in every detail, there are ideas in the themes that can be applied individually, so it's a good lab for Tiki design.
Again I want to give credit to Nelson Ko and Synergiq Solutions for sponsoring my activity in this project, enabling me to spend the time on it.