In the upper left corner, tap the hamburger icon or slide right to open the navigation menu.
Tap Events & Jobs.
Tap Job Signup.
From here, you may:
Search for an event.
Choose a date range.
Tap on an event to see more information.
Filter by Job, Start Time, or People needed.
Tap an event's unfilled slot.
Tap the "+" to enter the number of people who will be volunteering for this job.