I absolutely love this idea from Thoughtbot. Just like automated tools that check your HTML for syntax, formatting, validity, or whatever else, FormLinter checks your
HTML for best practices. Things like every input having a label, using correct input types, required fields, and more.
Doing all these things right is worth the effort: improvements like these improve accessibility and increase conversions. However, checking this sort of thing by hand is tedious and error-prone.
We were testing some forms in the ol' CSS-Tricks team chat and it was doing what it said on the box. On Geoff's personal site, it gave his contact form a "B" for not having matching labels for inputs and not having any fields required (seems like a fairly high grade?). The form was output from the mega-popular "Contact Form 7" for WordPress, also a bit surprising.
Many of the forms we tested bombed the app though. No word on that. Might be an HTTPS thing?