Shift and task management software

Hi all, I have an employee workforce of around 30 people. I am looking for software to be able to manage their shifts online as well as their tasks. It should work so that they're assigned certain shifts but will be able to shift themselves in the software etc. The task part should be so that I can set tasks the need to be performed at certain shifts or intervals, and that whoever is running the shift is accountable for them and has to mark in that he's performed the task and perhaps leave a comment. When I try to google I just hit a jungle, there doesn't seem to be a market leader. Does anybody here have experience with this type of software, what do you recommend? BR Platerising