Ubuntu's App Center Finally Supports Local Installs Again
If you regularly download .deb files and would prefer a GUI method of installing, Ubuntu has your back.
It's been a long time coming (and frequently requested), but Ubuntu will now allow you to install local .deb packages from within the App Center. This new feature should already be installed via a recent update starting with version 23.10 and up (with a catch).
Before you get too excited, it's not as if the Ubuntu App Center allows you to locate a downloaded .deb file and install it from within the UI. Instead, what you have to do is right-click a downloaded .deb file, click Open With, select the App Center, and allow it to finish the job for you. There also is a catch. Currently, the feature is only available to the Snap Edge channel, which requires you to switch with the command sudo snap refresh snap-store --channel=latest/edge. After you've switched channels, you'll then be able to go through the right-click process.
After a quick test of the Edge channel version of the App Center, I found it to be considerably more usable than the default. If, however, you don't like the idea of using software that's not been fully vetted and tested, I'd stick with the default and wait for the feature to arrive in the official release.
On top of that new feature, you'll also be able to update all installed Snap packages using the Update All options from within the management section. I will also mention that updating the App Center to the Edge channel solved a problem with a Firefox snap that was unable to update.
You can check out this Ubuntu app-center GitHub discussion to find out more.