The last development team I was on wanted a simple and fair way to assign people to unplanned, recurring tasks. Code reviews, QA, updating something minor on a client site, things like that.
Random picking apps somewhat worked but the same person would often get picked multiple times in a row. Excluding people from being picked was clunky. Also sometimes the assignee was just too busy already and they'd have to comment in a thread to say so. A simple random pick would turn into a team exercise.
A rotation that you didn't have to manually update would be ideal. So I built Pickle for this - it's for assigning people to tasks that aren't worth creating a user story for or having a meeting about. Its a simple tool but hopefully it'll let teams drop the overhead in task picking so they stay focused on things that are actually important.
I have a big list of features and improvements in mind if interest is there. I think that integration with tools like Github, Jira, Trello, etc... could be particularly useful.
Pickle App for Slack