This is basically the current design, with a few changes.

For each project, there are three extra things: A version number, a “What's New” box, and a subscribe button. You can subscribe to see when it is updated (If you are subscribed to the creator you are told automatically).

For updating it, it is simple. When you share it, and you modify it and save it, an “Update” button pops up. You can click it and it will share the new version (prompting you to update the version number and “What's New.” It will notify subscribers to both the creator and the project. That way, someone can tell when something new is added, and problems such as saving something that breaks the app can be avoided.

Of course, the whole “version number” and “update” thing can be turned off for newer Scratchers, and it will simply notify subscribers when you save a change.

Please support for a better version thing!

This is effectively version control, so +1.

Just updated the thread! Read the full idea!