Greengrass – Ubiquitous, Real-World Computing

$1.49 per device per year is very expensive for what amounts to library that is designed for vendor lock-in. In a market where there is a drive to push down the cost of devices, $7.50 (5 years) over the lifetime of the device is a substantial cost. And, unfortunately, it won't run on all your devices, only the high-powered ones, so you have to solve the problem on your own anyway for a full breadth of devices.