PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
UI Garage - Specific mobile and web design patterns for your inspiration
Helium - Helium lets you accept payments by credit card for anything you want to sell online.
Muzli - UI/UX and Design Inspiration Chrome Extension
PiPifier - PiPifier is a macOS 10.
Design Hunt - Curated design inspiration for everyone