You can track different metrics on each website, such as the rank of a website in a Google Search, the number of YouTube views, the number of retweets, the Amazon product rank, etc. Amazon provides several such trackers, more can be created on demand.
You can combine multiple trackers in one capture, for example, to track the number of views, comments, and likes for a YouTube video.
Blitapp reports trackers that are successfully found. You can see them in the history:
You can also track the metrics for the past 30 days under the Trackers tab in your History:
Click on a data point in any graph to get the corresponding screenshot:
You can find additional information about these categories of trackers: