Watch global / flow variable for change

Wich node can watch a global or flow variable and when the variable changes to a specific value trigger the next node?

I did not think this was possible, but hey yes there is a contrib node to do this.

No idea how it works, but it can monitor down to just part of an object in context, and it reports back the new written value as well as the previous value.
Works with both my memory (default) and persistent (file) context, just not sure if it can tell one from the other if they both have the same context name.

If you want to trigger a flow, then set this node up, look at the output and check with a switch node for your specific value, then the rest of your flow can follow.

Amazing. Just need to find a reason to use this!