Sometimes scribbles just don't cut it and you need more powerful curve tools in Google drawings. Google's curve tool does just that, based on cardinal splines. "The curve tool can be left open or closed, and can be filled or unfilled. You can also adjust points on curve after drawing it. It also replaces scribble tool in the icon bar, but original can now be find under shapes icon. It's also available via Insert > Scribble," informs Google.
Also, Google added a functionality in Google forms available to businesses, schools, and organizations using Google Apps that allow users to edit their own responses. Now, "when you create a form, you'll see option to allow users to edit responses. Users choosing to edit submitted responses will see their previous answers and be able to make edits, which'll automatically be reflected in your spreadsheet and in summary of responses," informs Google.
Users can edit their responses from the link in the form submission confirmation page or from the email confirmation, if one is sent.
More Info: Help Center documentation