In the trend of short, quick applications comes Mound Data Manager. If you've ever swapped out profiles for applications or wanted to snapshot them, this is your new friend.

Mound will try to find applications it is able to manage on your system. Any application that appears can have snapshots taken of its data and have data deleted, among other tricks.
In addition to plenty of sanity and safety checks, snapshots are taken and restored using tar, so your data should be just as safe as its always been.

As an example, I took a snapshot of Htop above, which manages only my local .htoprc. I then was able to mess around with some Htop settings and take another snapshot. These two snapshots can now be used to either restore default settings, or my custom ones. (Another quick way to restore defaults is to simply delete the data, which is available on the Application menu.)
In the future it will be possible to export these snapshots for use on other systems. They are stored as plain tar.gz archives currently, so you can do so already yourself, but there are no checks to make sure the data is valid yet.

Mound works by reading through your installed applications. Inside each application it will attempt to look for an X-UserData line inside the desktop entry, and if found, makes the application visible in Mound for managing. If one is not found, it will search through /etc/userdata (supplied) in attempt to find a default to show.
A UserData line in the desktop entry or in /etc/userdata tells Mound what files are available to manage. See a line for Empathy as an example:
empathy $CONFIG/Empathy;~/.gnome2/Empathy
$CONFIG is a shortcut for ~/.config using XDG directories. (Others are available, such as $CACHE and $DATA.) The two directories there are then scanned by Mound, and then the user is able to take snapshots of this data, delete the data, and revert older snapshots in place.
The shipped userdata defaults file currently only has support for 36 applications (those that are currently installed on my system). Give Mound a try, and if you see some applications that aren't listed that should be, be sure to let me know.
There are two ways to allow your application to be managed:
- Add an X-UserData line to your application's shipped desktop entry, with a value of a semicolon-separated list of files/directories to manage.
- Add a default line in /etc/userdata by contacting me or by making a merge request in Launchpad with your changes. No packaging changes required on your end.
I understand that most people will pick the second option -- this is perfectly acceptable, especially since this stuff is completely new. :)
And finally, the download links:
Download, give it a try, and let me know what you like and what you don't. Enjoy.