EasyBloom is a very cool product that will analyze the immediate area that you have a plant growing. You stick this in the ground next to the plant let it collect data for 24hr then you separate the sensor from the data collection section and plug that part into you PC
The device then will upload the data to easybloom, you enter the plant type that the sensor was associated with and easybloom will give you information on what you need to do for the associated plant to maximize growth and health.
The team that built this licensed technology from NASA to give you a detailed analysis of what is happening with your plants.
No monthly fee. Just purchase as easybloom for $59.00 and you get lifetime access to the companies website and data analysis system.