Contrast Check
Read the contrast of any color pair
Pick a foreground and a background from the page and see the ratio against both accessibility levels as you go.
Chrome
This is a Chrome extension. A store listing is on the way. Until then you can load the unpacked folder from the project, or write to me if you want a note when it is live.
Privacy
Work stays on your device. There is no analytics. See the privacy policy for what each permission is for.