UProc for Sheets - Boost your sales, marketing and IT tasks from Google Sheets
TrackingSuite - TrackingSuite is an all in one leadgen, website auditing , seo , crm prospecting tool.
Sheetlist - Discover free Google Sheets for marketing, finance and more
Email Verification on Google Sheets - An add-on for email verification directly in Google Sheets
Drift + Salesforce Integration - Create and track leads from Drift in Salesforce
Reply: Live Tasks - Convert prospects into customers with Live Tasks suggestions