A little piece of cozy software I want: a collaborative ELO ranking.

Put in a few dozen options, then show the user repeated comparisons between pairs of options and ask which they prefer.

Then calculate a ELO ranking of the options based on those preferences.

If other people can also vote, you could get an emergent team ranking on a question, and even be able to filter down and see individuals' rankings, and compare where they differ.

This would be a useful little collaborative widget I'd use in various situations.

Any particular toy version of this would be hard to coordinate your team to use on some arbitrary platform, and there's no obvious business model for someone to make one as a business.

A piece of software that I wish existed but doesn't.