Segment
Segments’s documentation pages includes a What this page helpful? feature with a Yes and No rating system. The feature appears fixed on the right side of the page and at the bottom.

The feature at the bottom of the page:

If you click Yes, a modal with a text area appears for you to send more feedback:

If you click No, a modal with a text area appears for you to send more feedback:

After you click either option, a link appears to allow you to send more feedback.
