LightShot, Greenshot, Camtasia, Snagit, Snipping Tool, ShareX, Skitch, PicPick, FireShot, QuickTime Player, Spectacle, FastStone Capture, Screenpresso, ScreenFlow, Evernote Web Clipper, PixelStick, Awesome Screenshot, Xnapper, Flamory, Pixel Ruler, Free Ruler, JR Screen Ruler, FocuSee, KRuler, Screenshot Captor, JR Screen Ruler Pro, WinSnap, DuckLink Screen Capture, Meazure, A Ruler for Windows, Pixel Ruler for Android, MWSnap, PMeter, Screen Ruler Professional, ScreenRuler, Pixus, ReadingRuler, PixEase, Measure Schmeasure are some alternatives to Shottr.