Greentest is an APP based device for smart express analyses of nitrate levels in fresh fruit, vegetables, meat and fish, as well as water hardness (TDS) and background radioactivity levels detector in the surrounding area and in the particular objects. To start testing, simply switch on your bluetooth on your mobile phone or tablet and get the APP connected to your device. The safety and accuracy of the device is internationally certified and proved by CE, FDA, TUV, RoHs, CQC, etc.