Form Tips module uses JavaScript to move form description/help text to tooltips.
It helps to reduce form clutter by removing form descriptions from the page and only displaying them when needed.
Drupal 8
The functionality is the same as earlier versions but with a bit easier to modify CSS and the image was replaced with CSS.
Drupal 7 & 6
Examples
Please see the screencast showing how the Views 6.x add fields form looks with this module enabled.
Short name
formtips
Supporting organizations
Maintenance
Development and maintenance