Would be nice to have the installed size available in the install tab. https://i.imgur.com/kzGC8dn.png Bottom to the app subtitle there would be place. And than the app list can be sorted by size.
Cause have an overview about the installed app is the app launcher for. Here it is usefull also when you have less disk space (VMs or SSD)
+1, this would be nice. Sorting by something other than the default is tracked with Bug 383518. Since we do have a real toolbar in the Installed view, we can probably put the sort order combobox there now.
You get to see the size in disk if you open the application. Note that this size information will always be misleading for the packagekit case as downloading an application may imply removing dependencies too.