How about a live filter?
Created by: universalhandle
The "Add new" list gets long fast, and as we get more extensions whitelisted, it's only going to get longer. What about a live filter on names, descriptions, compatibility? We could even trivially set a sane default on the filter of the current CiviCRM version so that the initial view is of only extensions compatible with your version. There's no reason the live filters would need to be limited to the "Add new" tab; we could use them across all tabs.