Meazure - What are the dimensions of that image? How big is this window?
Tribe of Mentors - Short life advice from the best in the world, by Tim Ferriss
ScreenRuler - ScreenRuler lets you measure objects on your Ubuntu desktop using six different metrics.
MentorCruise - Personalized mentorship experiences
Bluegrams Screen Ruler - A lightweight and configurable ruler tool for Windows Desktop.
Frontend Mentor - Supercharge your front-end skills by building in a real-life workflow. Solve real-world HTML, CSS and JavaScript challenges whilst working to professional quality designs.