Yes, primarily vehicle size requests (some disabled people need a larger or higher vehicle). Many local taxis companies (if they exist where you are) are not so flexible. Somewhere like New York, disabled friendly services are hard to come by. There are things like the city's access-a-ride, but disabled people shouldn't have to go through such bureaucracy just to pop down to the shops when they feel like it. I've lived in more civilized countries where taxi apps allow you to order specifically wheelchair friendly taxis etc. that will arrive in moments. Of course, none of these are the actual solution to the problem of accessible transport, but there are some advantages to the apps over the existing taxi system in this regard.