What are some alternatives?
When comparing glitchi and Pixus, you can also consider the following products
generative.app - Transform your images into compelling algorithmic art
Meazure - What are the dimensions of that image? How big is this window?
Glitch Wizard - Create trippy glitch photos and animated GIFs
Bluegrams Screen Ruler - A lightweight and configurable ruler tool for Windows Desktop.
CharMap - Unicode character viewer and keyboard for iOS
PMeter - PMeter is a very handy pixel meter.