The latest releases of Firefox web browser and Thunderbird, both Ubuntu’s default apps, are also ready for upgrading.
Other changes introduced include sandboxed security on iFrames; ‘click to play’ warnings on out-dated plugins, and larger icons in the ‘Awesome Bar’.
Firefox’s e-mail sibling Thunderbird adds a new menu button (familiar in style to that used in Google Chrome), though its introduction doesn’t affect the App Menu.
Elsewhere there are crash fixes, performance tweaks, and a properly functioning spell check.
No download button needed to get any of these releases: just open the Update Manager/Software Updater to upgrade to them.