Form Filler is a free Chrome extension which can instantly fill web forms with dummy data.
The package is aimed at developers and anyone else who needs to test web applications, but it could also be handy as a quick way to fill in surplus entries on a form.
Basic usage is simple. When you're at a web form, right-click the page and select Form Filler, then Fill All Inputs to complete every field on the page, Fill This Form to complete the currently selected form, or Fill This Field to complete the selected field only.
All fields are complete with random but realistic data. "Name" fields will get a name, "Address" an address, "Email" a valid (but fake) email address, checkboxes will be checked (or not), options selected in lists, and so on.
Form Filler is intelligent, for example correctly repeating previous data in a following "Confirm" box, and ignoring CAPTCHA, hidden, disabled and readonly fields.
It's also extremely configurable, with support for custom fields and generating dummy data based on a regular expression.
An excellent testing tool, easy to use but with enough configuration options to handle most of the scenarios you'll face.