The 'Capture, Explain and Send Screenshots' extension is available from the Chrome Web Store. Like other screenshots extensions, it allows you to screenshot a selection of a page, the visible part of a page or the entire webpage. This extension, however, allows you to also annotate those screenshots before deciding to download them or save them to your Google Drive.
While it's annotation tools don't live up to the likes of Skitch, the ease of doing this all within Chrome makes it a good contender for some quick pointers on a screenshot as can be seen below. The save to Google Drive feature required installing a second extension by the developer - Checker Plus for Google Drive - and in hindsight, perhaps it would be better to limit the amount of extensions that can access my Google Drive account.
In terms of usability, it was ok. It did the job, the text sits in a white box above whatever you're annotating over, which is not great unless it's a white background, but like I said, for the ease of being able to save direct to Drive, you may make do. It had some extra features like blurring parts of an image, but this required an upgrade. It does also stamp the URL of the page you took the snapshot at the top and bottom of the image, so unless you have a white border each side, it ends up obscuring text and images you were trying to capture.
The Awesome Screenshot extension is also available in the Chrome Web Store, make sure you install the extension, not the actual app - they function differently. This also provided the options to capture various parts of the page, with added features such as delayed capture, uploading an image, and capture desktop - this last feature allows you to select a screen from an open app/window to capture and edit.
This extension also annotates and edits images, you can even resize the selection you capture before committing to capturing it! It did, however, lack the feature to save to drive. You can store you work in your Awesome Screenshot profile, download the image or copy it to clipboard.
It terms of usability, it was the better extension by far. The text wasn't boxed in white, you can blur parts of the image without upgrading, you can highlight parts of the image with a colour and the URL wasn't stamped onto the image as with the former extension. The lack of Google Drive functionality isn't the end of the world, after all you can download it to your local Google Drive folder, which will in turn sync to your cloud-based Drive.
Overall: Awesome Screenshot wins hands down due to a slicker interface and better editing functions.
I'm passionate about Music, Music Technology, EdTech and Education. I started off my career as a musician and sound engineer then quickly progressed into teaching.