Miro Startup Program - $1000 to set up team collaboration
SimilarWeb - SimilarWeb.com is a website analysis tool that gives you analytics information for any website.
Aircall for HubSpot - Document and organize every phone call instantly in HubSpot
Site Rank Data - View historical rank information of websites via time series charts.
Intercom on Starting Up - A book about growing a startup
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.