Welcome to iMore! Swift Playground is marketed toward kids but people of all ages who are interested in learning how to code can learn from it. Actually, iMore just posted a blog article about Swift Playground earlier today. Check it out here: Trix may be for kids, but Swift Playgrounds should be for everyone | iMore
Everyone should be able to use it. I believe it's geared toward a younger audience, but no reason everyone can't use it. I am totally gonna try it out.