Photon is a free tool for capturing, annotating, processing and sharing screenshots. (And it can capture desktop videos, too.)

Capture types are few: you can select the full screen, active window, rectangle, circle.

Once you've done that, the area remains highlighted and a couple of toolbars appear around it.

You can annotate the image with simple drawing tools: a pen, line, arrow, rectangle, highlighter, text caption.

The results can be shared on Twitter, Facebook, Pinterest and VK, uploaded to the developer's free online storage service for instant reuse (you'll get a link you can post anywhere), or saved locally.

Click the Google icon and a browser window opens to maybe identify this image (name a person, say), and display similar images.

Clicking "OCR" extracts and displays any plain text from your image.

There's also a tool for recording a video of your desktop activities. This can optionally show your mouse cursor and a mouse hotspot, and may be saved as MP4, AVI or OGG.

What’s new in version 2.4.3.1?
- Small bug fixes - a text rendering bug and an errant equation referenced in the chemistry library has been fixed.