Of course, most of the extensions have the typical capture options: visible part of screen, selected area, entire page, and more. They also include annotation tools. All three discussed here sync with Google Drive.
Snagit and Clipular each offer scrolling capture. I found Clipular's to be rather clunky when trying to select the area to capture, and Snagit's is nothing more than "capture entire page"; you have no control over the scrolling selection.
Here's a look at some of the special features of each:
One of Awesome Screenshot's best features is the delayed capture, which gives you several seconds to perform an action before the shot. For instance, you may want to click on a drop-down menu to capture it in the shot. A.S. also has a Chrome App, which provides additional annotation and image editing capabilities. A.S. has what I consider to be the best annotation tools of the three (click Launch app for advanced annotation).
Clipular is essentially screen capture partnered with bookmarking. Clips can be grouped in "boards" (much like those in Pinterest) and shared to social media. Clipular has both free and paid versions. The free version can be difficult to find once you have "subscribed" to it. Clipular will open an upgrade page, and you need to click dashboard page at the bottom to enter the free version. Clipular also has both an extension and an app.
Snagit offers both screen capture and screen recording - with audio. Both the app and the extension need to be installed from the Chrome Web Store. Snagit works in Chromebooks, as well as in the Chrome browser on other machines. You can place captures directly into a Google doc or other workspaces. And, of course, Snagit has annotation tools and sharing capabilities.
Another great feature is that screen recordings of 20 seconds or less can be saved as animated GIFs (sound not supported). If you don't need sound and can convey your message quickly, a GIF may be the way to go due to the smaller file size
Because Snagit syncs with your Google Drive, all captures and recordings are saved automatically to a TechSmith folder in your drive. Awesome Screenshot and Clipular require manual saving.
GAFE schools using Google Classroom can create announcements or assignments that include screen recordings from your drive. Students often find video much more engaging than reading a document or tutorial.
One downfall of Snagit for Chrome is it's lack of annotation tools. It contains only the basics: text tool, ellipse tool, rectangle tool, and arrow. Six colors are available for each tool. Text formatting includes bold, Italic, underline, and strike-through. The shape tools do not allow for line thickness formatting. But all-in-all, that is enough for me.
No one of these apps is the best; each has one or more features that the others don't.