ImgurSniper is a versatile tool for capturing and sharing screenshots.
At its simplest you can tap the system tray icon or press the (custom) hotkey. Draw a freehand rectangle on the screen around the area you'd like to capture, it's instantly uploaded, and a browser window opens at the Imgur URL to show the results. Pass on the same address to anyone you like.
Right-click inside a window to detect and upload a capture if that window only.
Press the space bar while the program is active and it switches to Paint mode, allowing you to draw freehand on the screen. Press the space bar again to switch back and select the capture area as normal.
A GIF mode works in a similar way, but captures multiple images over a defined period to create an animation.
A Ctrl+A option takes and shares a screenshot of all your connected displays.
If you don't always want to use Imgur, the program can be set up to save captures locally or copy them to the clipboard.
The program also has some uses entirely outside of screenshots. Once installed, right-clicking any image file displays an "Upload to Imgur" item which uploads and shares it online.
ImgurSniper has a lot of functions and features, but they're not always easy to discover. While other capture tools have menu bars or some other interface element to help you, this one relies on you knowing that, for instance, you need to hit the spacebar to activate Paint Mode. Still, the program has a decent Help file to highlight these points and overall it's worth having.