With Nimbus, you can capture the screenshot of the whole web page including areas that require horizontal or vertical scrolling. The add-on can also be used for capturing any specific region of a page or just the visible content as a high-quality PNG image.
Once a screenshot is captured, it automatically opens up in the built-in editor where you can annotate the image with common drawing tools, apply text callouts, crop the blank areas or even blur select areas of the captured image (useful for hiding sensitive information like credit card numbers printed on receipts).
The annotated screenshot can be saved locally or you can upload it to Google Drive directly from the Nimbus editor.
Such an extension is especially useful for Chromebook users as Chrome OS wouldn’t support external screen capturing apps.