Hi Gary. This is an excellent idea for a product that is much needed in schools. Teaching proper device etiquette and digital citizenship is important, but let’s be honest – there will always be (many) students who use their devices for non-educational purposes in class. If this was technologically possible to implement, I think you would have a winner here. The point made by others about it being cross-platform would be key to its success. The issues raised by some others need to be addressed – privacy concerns, reluctance to opt in, how to prevent students from closing Sentinel or just rebooting the device, etc. I recognize that a subscription based service would provide the most revenue in theory, but this does not seems like a product that would be suitable for that model. I see subscription based services as continually providing new content or features, unlike your product. I think you should ask for more money. Great job on both the elevator pitch and the website.