The feature I wanted to use the most, the ruler, when enabled would make the web page freeze & I cannot scroll down to read the rest of the article. There should be an option to set multuple rulers in different colours, and more option for heights as well as widths, and options to set the rulers at fixed positions on screen that can be saved & enabled at 1 click. Dyslexia/dyspraxia/dysgraphia & other developmental disabilities manifest differently in different people. I don't mind paying because I really need aid reading, but I don't use all the other features & the one that I really need doesn't work very well. It's a pity.