When there is a will, there is a way. This is how I would do it. I'm not saying this is the best way, but it is one way...
Install virtualbox. This is a free, open-source program that allows to run Virtual Machines. You can run just about any operating system you'd like using Virtualbox, but for the sake of example, let's install Android.
First, install Virtualbox:
sudo apt-get update
sudo apt-get install virtualbox
Next, for simplicities sake, let's grab a pre-installed ova image of the Android O.S. I'm choosing Android because it is also free and open source, and you don't need to break any laws to do this.
Download the image from here:
http://sourceforge.net/projects/android-x86/files/Release%204.4/android-x86-4.4-RC1.iso/download
Next, open Virtualbox and configure it. Follow the instructions from this site, there may be better tutorials out there, but this is first one Google threw at me;
http://www.learn2crack.com/2014/02/install-android-4-4-kitkat-pc-using-virtual-box.html
It should be relatively painless. After that's done, install Uber in your new Android V.M. from the play store. I'd like to note that I have had different experiences doing this, for instance sometimes Google will randomly cancel my accounts, if they were created in a V.M. Your milage may vary. If you can't get the Play Store to work, install the VirtualBox Guest Extentions package (you should anyway), and import the APK file through a shared host-to-guest folder.
An alternative to the procedure above would be to use WINE, a program that allows you to run Windows software natively within Linux which is a wrapper for Windows software, which allows it to run (sort of natively) in Linux. (Thanks, Michael). I'm not sure if this would work for this particular app, I don't use WINE personally, because Windows is akin to a submarine with a screen door, but whatever floats your boat, I suppose. (I run windows software in a virtual machine for security reasons, to keep it confined from the rest of my system).
Edit: I just noticed you have a high reputation, so you may already know all about WINE and V.B. I also would like a simple solution for running android apps in Ubuntu. I'd think it would be possible to run a java applet without running an entire other O.S. on another linux system. I hope this answer helps someone.