UI Sources - Mobile design patterns & interaction videos
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Product Hunt - A website that lets users share and discover new products
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Page Flows - User flow design inspiration for mobile & desktop
Bigtent - BigTent is a web-based organization and communication portal for groups.