Famous First Websites - Discover what popular startup websites looked like at launch
Google Analytics by SumoMe - The easiest way to see your Google Analytics
Waybackpack - Download the entire Wayback Machine archive for a given URL
Metric.live - Real-time and advanced periodic alerts for Google Analytics.
Youtube++ - extension to show publishing date of related youtube videos.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.