For those of you who commute in San Francisco or are looking at your next trip in San Francisco, you can now purchase the $5 Day Pass on their official ticketing app called MuniMobile and ride Muni buses, trains and historic streetcars as many times as you like through 11:59 PM.
MuniMobile for iOS
MuniMobile for Android
For more details about this deal, visit this page [sfmta.com]
For information on how to use a ticket, visit this page [sfmta.com]