If you run btrfs with snapper, snapshots are already being taken: one an hour, one either side of every package transaction. Reading them back has meant the terminal. Wisp puts them in the top bar of GNOME Shell 46 or newer, and the extension is one menu and one settings window.
What the menu does
Each snapper config gets a section, newest snapshots first, and the pair around a package transaction is shown as the one event it was. There is a button to take one with a description no cleanup rule will remove, a delete that confirms what goes, and open-in-Files for reading one as it was. Rename, mark important, change its cleanup rule, turn read-only off, all from the menu. Everything changed since a snapshot is searchable; for a package transaction, it is exactly what the transaction changed.
Restoring is where it earns its place: pick files out of that list and put them back, or roll the root filesystem back. Both are root’s either way, so Wisp shows the command and copies it rather than running it.
The root question
A snapshot tool is a lot of trust to hand an extension, and the permission model is worth reading. snapperd does not use polkit at all. Each config carries its own allowed-users list in /etc/snapper/configs, and both lists start empty, so a fresh install tells an ordinary account nothing. For a config you are not on, the menu shows the command that adds it, including SYNC_ACL, the step that puts an ACL on the snapshot directory; without it, the snapshots list but their files cannot be opened. After that, Wisp talks to snapperd over D-Bus as you and runs nothing as root; the systemd timers go through systemd’s own polkit asking. There is also an optional polkit gate for the menu itself, in the preferences.
Before you install
snapper is the requirement, and it usually is not installed. The extension detects that and hands you the install command for your distribution; there is nothing to list until a config exists, and the settings window builds the command to create one. util-linux and btrfs-progs power the Storage page, btrfsmaintenance the balance, scrub, defrag and trim jobs on Schedule, and polkit the optional lock and the timer switches. polkit and util-linux are on practically every desktop; snapper is the one that is not.
It installs from extensions.gnome.org or a release zip, is GPL-2.0, and version 1.0.10 landed on 24 September. The repository dates to August, which is the honest caveat here. The warning that bites people most is built in: if /etc/fstab names the subvolume it mounts at /, a rollback would do nothing, and Wisp says so instead of letting the reboot say it.
My read
The gap it fills is real: snapshots you already take, readable without leaving the desktop. The restraint is what makes it easy to say yes to. The things it cannot do as your user, it hands you to run, and it spends its warnings on the one rollback that would silently fail. For an extension this young, that instinct is the most convincing thing about it.
Source: the project repository and its extensions.gnome.org listing.