You mentioned that Uber specifically forbids using their API for price comparison. Aren't you worried that they may implement something so you can't use internal APIs? I'm pretty sure none of the companies would like this app. Even though I think this is great and promotes fair pricing

It's possible they do that, but it's difficult to block third-party clients entirely. Changes to APIs can generally be worked around.

We need to make terms like that unenforceable in law with penalties if they do that anyway.