The worst!
We generally visit Spain for a couple of months at a time, a couple of times a year and have spent time in all the large cities. So, we have a lot of experience. No ifs, no buts, Cabify Sevilla is the worst taxi app we have ever experienced in Spain. Actually, to be accurate, there's not much wrong with the app itself, just what happens when you use (or try to use) it. If your taxi actually arrives And actually takes you to the location you requested, you should immediately rush out and buy a lottery ticket, because days that lucky only happen once in a lifetime!