ContourShot

Shape your screenshot around the details you need. Start with a rectangle,
click the plus handle on any edge to add a vertex, and drag the vertices
to create a custom outline. The selected content stays visible while the
rest of the screen is dimmed.

Capture a polygon, a monitor, or an application window. Optionally straighten
edges with an adjustable tolerance from 0 to 45 degrees. Save transparent
PNG files and copy them to the clipboard. Undo and redo outline edits.

Designed for GNOME on Wayland. The current interface is in Russian.
This snap requests access using the system screen-sharing picker before
each capture. One monitor is captured at a time. If the desktop does not
identify the selected monitor, a single-monitor setup is required.

To use Print Screen, create a custom shortcut in your desktop keyboard
settings with the command /snap/bin/contourshot and free that key from its
previous action. This snap does not change global keyboard settings.

Screenshots are saved locally in ~/Pictures/ContourShot. No account,
telemetry, remote screenshot processing, or cloud upload is used.