OKUPIED
http://www.okupied.com/Changing the way individual landlords manage their business
OKUPIED enables individual landlords to be more organized and efficient by providing them with simple tools to manage their properties "on-the-go". It eliminates the need for spreadsheets, paper-based accounting, and cash/check handling for rent payments.
Angel list: https://angel.co/company/keepokupied
Member count: 1-10