Lean Analytics - A/B testing React apps made easy
MockServer - Easy mocking of any system you integrate with via HTTP or HTTPS.
SEOTesting.com - Easily track the changes you make to pages and websites, to see if they have an effect on Google rankings and clicks.
Beeceptor - Unblock yourself from API dependencies, and build & integrate with APIs fast. Beeceptor helps you build a mock Rest API in a few seconds.
Decidr - Make better decisions with quick A/B polls
Webhook.site - Instantly generate a free, unique URL and email address to test, inspect, and automate (with a visual workflow editor and scripts) incoming HTTP requests and emails.