Katalon Studio is Open Source Test Automation which allows you to automate Web UI, Mobile Application (Native, Hybrid, WebView).
Katalon is developed by KMS technology. Katalon is the totally free tool which makes it more unique than the existing paid automation tools. It has inbuild rich libraries which allow the tester to write the test quickly and efficiently.
You can download the Katalon Studio using below link and start using from today.
Katalon Studio Tutorial