What are some startup ideas that you can't or don't want to pursue for some reason but honestly think might have legs and/or that you would like to see exist in the world? And that anyone who likes them is free to grab and run with?

Here are three of mine:

* Shamery: a bug hall of shame; anyone can submit bugs they've found in web, mobile, and desktop apps and vote on the worst to publicly shame companies into fixing them. The business model might be that it doubles as a job marketplace that connects high quality QA pros with the companies that need them. But really I think this would just be a funny website that would improve average product quality AND produce fun drama

* Router: input a list of job descriptions that interest you and your current experience and qualifications; the output is a custom curriculum for you to pursue, built from a curated collection of high quality resources available online, like MOOCs, blogs, learning projects, book PDFs, online playgrounds, etc. Not just a bunch of resource links but a learning path, with a specific ordering, specific assignments, etc

* Rivals - find leaderboard rivals for single player games like Geometry Wars and Slay The Spire. Join up into leagues, run customized competitions, compete across platforms