looking for a chrome extension. there are many free tools

If it is a Saas then it's important to engage with visitors, and win their trust. That'll definitely increase the conversion rate. So, I recommend Senja- (https://senja.io/) for the testimonial showcase on your website. And Notificationpro- (https://notificationpro.simplef....) for use of social fomo, collect leads and use many widgets on your website like header bars, countdown timers, popups, customer satisfaction tracks, and more.

Visual Studio Code if you do some coding in your startup