This app was mentioned in 7 comments, with an average of 115.86 upvotes
I've been using GoA2B. They've added almost all of the major rideshare services in Austin.
I'll give ATXrides a spin to see how it compares. However, A2B has the benefit of working in other cities, too.
Just FYI I would not stay at Tigard Square unless you're only there for the event. The area is about a $30 Lyft Ride each way into and out of downtown Portland, Uber seemed to have less of a presence than Lyft but download Zailoo on your phone and it will compare options. Also if you haven't used Lyft or Uber before make sure you sign up with a discount code which will give you free credit on each ride, it's pretty significant with Lyft for the first time. Then if you go with other people, have them also sign up and you can get a few free trips.
I went to the showcase in December and after the event a few of us walked over to a sushi restaurant nearby, I think Sushi Hana. They have a big booth that fits like 12-14 people and the prices were really cheap.
Just use the app called Zailoo, it even factors in surge pricing
Zailoo - Ride Estimates For Uber, Lyft & Taxi by Delta Prairies, LLC https://appsto.re/us/mVf26.i
https://play.google.com/store/apps/details?id=com.zailoo.xroads&hl=en
Edit: links
Zailoo - checks all Uber, Lyft, Curb, etc prices and lets you compare them all.
How is it different/better than goa2b?
https://play.google.com/store/apps/details?id=com.zailoo.xroads