craigslist - craigslist provides local classifieds and forums for jobs, housing, for sale, services, local community, and events

UI Movement - The best UI design inspiration, daily

Bedpage - Bedpage is a classified ad posting a website that comes as the alternative to Backpage and offers almost all the major services to post for multiple categories.

UI8 - Carefully crafted UI design assets

Facebook Marketplace - Marketplace is a convenient destination on Facebook to discover, buy and sell items with people in your community.

UI Garage - Specific mobile and web design patterns for your inspiration