Here is the list
1- Wiggio
Wiggio makes group work much more easier as its easy and straightforward design provides everything you need to work productively in your groups. It is simple to use and has a very nice and flexible interface that makes it easy for students, parents, and teachers alike.
2- Doodle
It is a tool for scheduling meetings. If you are planning a meeting with different people and you don't want to impose your opinion on them as for the timing of that meeting then use Doodle to make a poll and invite your group members to vote for an appropriate time when they can all meet. It offers a democratic way for scheduling meetings
3- Sign Up Genius
This is a free online tool to create and manage group sign up lists. It offers its users several services such as :
- Wizards for creating sign ups
- private or group sign up
- automated email reminders
- customizable templates
- Easy administration tools and stats
4- Volunteer Spot
this is another free tool that allows its users to create online sing up forms and volunteer scheduling. It does not require any registration or software installation. Just go ahead and give it a try.
5- Sign App Now
Sign App Now is a great application that lets users create simple and easy sign up sheets. It has two versions one is free and one is premium with 5 dollars a month. I think the free version is enough for you and has the basics of making a sign up sheet.