I'm not sure if this is going to be helpful...
But as a frequent business traveller, I'd NEVER download an app for this use. I'd use a recognized brand like Uber, which I, as a traveler, probably already have installed.
On the other hand, if you integrated as a chat-bot in a platform like Facebook -- and others -- that I already have installed, then it is possible that I'd give it a try.. Installing an app is too heavy-weight for anything that I'm not going to use regularly, especially if I have to also create an account, hand over personal info, etc.
My question to you would be WHY? What is in it for me? Clearly a limo company would love your product, but me as the consumer -- what value does it bring me?