The FreeStyle Libre is the first flash glucose monitor, and the treatment people lobbied for in the Fight for Flash.
It's made by a company called Abbott which prices the sensor at £57.95 a sensor which lasts up to 4 weeks.
There is an app you can download onto your phone called FreeStyle, once you download it and calibrate it with the sensor you can use your phone as the reader which shows you graphs and readings of your sugar levels.
Abbott also have a reader which you can use instead of your phone which is £57.95
Here is a video on how to apply the flash glucose monitor by Hey Pharmacist: