Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Interfacer - Collection of more than 200+ free design resources
StatusGator - Monitor all your hosted applications, vendors, and websites, and keep your team informed of outages. StatusGator is the world's premier status aggregator, status page, and website monitoring tool.
Facebook Design Resources - A collection of free resources made by designers at Facebook
WrapAPI - Build an API on top of any website
Freebiesbug - Collection of the best free web design resources.