Download the Flywheel App and use promo code SEACENTER and you will get a free $10 to use. We used it and it covered our cab ride.
Flywheel website, click here
The App is real easy to use. The App shows where you are and you can select from pick up locations. Once you hail a cab via the App, you can see where your cab is and watch it on the map. It gives you real time updates as to how many minutes away your cab is, and it tells you who the driver is. Once onboard the app stays live letting you select the tip amount. You never pay the cab driver as everything is done through the app. Yes, you have to add a card to it so it can charge you, but it is super easy and convienant.
Try it out today!
It is currently available in LA< Seattle, and San Francisco