Expand/Collapse Pages In Admin Manage

Hi,

I posted this in How To’s, but actually think I may need a plugin for this!

https://www.ads-software.com/support/topic/200727

In short, I predominately use pages and subpages rather than posts. To stop my Admin/Manage page getting stupidly long with subpages, I would like to be able to collapse and expand subpages from their parents, so in essence I go to Manage and on entry only see 6 pages, and then have the option to expand various ones to see subpages (and possibly subpages of subpages!)

I hope this makes sense and can be done! Any help would be greatly appreciated, especially if there is already a plugin out there!

Many thanks,
Matt