SignUpGenius is a free website where you can create electronic sign-up sheets for all sorts of events, such as, potlucks, organizing meal delivery for friends, asking for volunteers to help with an event, etc. It's really easy to use and it will even send a reminder to the person that signed up so you don't have to! 

Register at:  https://www.eventbrite.com/e/making-life-easier-with-signupgenius-tickets-394461915207