A collection of visual programming tools that mention vvvv as a source of inspiration:

• XOD is a visual programming language for microcontrollers. mentions vvvv here
• MeeMoo is a web-based creative tool maker... mentions vvvv here
• Cables is your model kit for creating beautiful interactive content. With an easy to navigate interface and results in real time, it allows for fast prototyping and prompt adjustments - mentions vvvv at the bottom of the main page
• vvvv.js is a great toolkit for prototyping and developing rich data visualisation, advanced user interfaces, games, and more
• ThreeNodes.js is a visual dataflow based WebGL editor that uses drag and drop to create a scene. mentions vvvv here
• dflow is a minimal Dataflow programming engine
• PNI - a node based visual programming environment
• fnk is an online visual programming environment that uses a dataflow approach for the analysis, processing and synthesis of image, sound and other data in real-time. mentions vvvv at the bottom of the main page.

Please don't add just any visual programming tool (there are hundreds) but only those that claim to be directly inspired by vvvv.