SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Briefly - TL;DR - Highlight the internet and share on social media
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.
Glean.co - Personalized learning for educational video lessons
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
Stringmark - Stringmark is an extremely easy-to-use Chrome Extension that allows you to save Links and Texts that are relevant to you.