Node-RED is a beneficial tool to integrate all kinds of protocols and web applications services and cloud computing and best for IoT and Automation. I enjoyed using Node-RED mostly on hardware integrations.

we can easily use it to develop applications in javascript.

The best thing about Node-RED is the ease with which we can program. Also, there is a node for everything; for MQTT, HTTP, JS Functions, SQLite, delay, split, I can go on and on. Since it supports npm packages, it is effortless to create any complicated flow. The other thing is since it is visual, it makes it that much easier to troubleshoot. The debug node is also very useful.