Spotio - The App for Tracking Door-to-Door Sales
CiviCRM - A Constituent relationship management for the Civic Sector
Sales Rabbit - Sales Rabbit is the industry standard canvassing and door to door sales app.
Odoo CRM - Open Source CRM
Resco Mobile CRM - Resco is one of the global leaders on the mobile CRM market.
Less Annoying CRM - A simple customer relationship manager made just for small businesses. Manage contact info, track leads, and never miss a follow-up.