Loopple - With Loopple, you can build your next Bootstrap Dashboard easily using drag and drop.
UI Flow Cards - Construct web pages with ease, using cards
Launch - Free book featuring practical tips from top Product Managers
Wannathis - 3d illustrations and freebies
Chartmat - Build dashboards and apps on top of Google Sheets
The User Interview Exchange - Give a user interview, get a user interview - It's all free