Productivity

http://pdftoimage.com/

https://www.pdfescape.com/

Convert multiple PDF pages to images on a Mac: http://www.mactricksandtips.com/2013/03/how-to-save-pdfs-as-jpegs-including-multi-page-pdfs.html

https://www.onlineocr.net/

YouCanBookMe: http://youcanbook.me

ClassroomScreen: https://classroomscreen.com/

Timer: http://www.timer-tab.com/#fullscreen