fuel or temp gauge not reading correctly?

I just learned about an electronic device that sounds like it can be used on any gauge and any sending unit, and make them work together properly. ( temp sender with temp gauge, fuel sender with fuel gauge)  I haven't used one yet, but I know someone who has used one, and he said it works well. The company is Spiyda, and the devise is called Gauge wizard. They are in the UK, and the Gauge Wizard is priced at 44 British Pounds. If you search Spiyda Gauge Wizard, there are several you tube videos that show how it works and how to program it. It sure looks promising to me. 44 pounds is about $60. I have no affiliation with this company, and nothing to gain financially. If anyone has used one and can share their experiences, I would be glad to hear what they have to say.