Node-RED: A visual tool for wiring the Internet of Things
nodered.org
nodered.org
1) What's the use case?
2) Who is the audience?
An other tool with a similar interface is Autopilot (https://autopilothq.com/, not affiliated). That one let marketing/product people tune email campaigns themselves where they otherwise would have had to ask developers for help. User events from our product were forwarded to Autopilot and marketing/product could create triggers and quite advanced user journeys (like the onboarding flow) from the event stream without coding.
eg, this is a 'flow' I use to turn my desk lamp off when I turn the room lights off - http://i.imgur.com/ZuVHhaN.png
Of the inputs on the left-hand side, the top row takes a setter from an mqtt queue (via which I tie in with homekit/Siri), the middle row polls Hue's state for the room, and the bottom row listens for IR remote events. And then the blue element labelled 'Desk' is actually a switch on a web UI; it just happens to have a happy side-effect of marshalling the various inputs together.
This 'flow' went from inception, to "I'm happy with it" in 5-10 minutes, and allows my Wemo switch (the output/actor on the right) to integrate with several products that the vendor have zero intention of ever supporting. It's easy enough that I only included the IR inputs as they took less than two minutes to add, making a very low barrier to "wouldn't it by nice if .."
It's not code-free (I feel like I'm near-constantly writing functions to translate values between different systems), but it's an incredibly rapid way to build IoT-style automation.