Don’t waste your money. Get the cheapest code reader from autozone. When the check engine light comes on look up the code on the internet or just let autozone read the code for free. Fixit is only reading the code and telling you what it is.
Its just a bluetooth OBD2 scan tool. If you get a CEL (check engine light) you can use this to find which error code is being reported and in some cases reset service indicators.... then search the code and get pointed to whatever sensor or system is failing..ie if you get a p0131 code, Enter that in your search bar with the brand of car, results will tell you it has to do with one of the oxygen sensors in the exhaust..