Urban Rivals Battle Calculator is an add-on for the Firefox 3 Browser that uses the popular Greasemonkey add-on.
In order to use it you need Firefox 3 or better which you can get here: http://www.getfirefox.com
And also Greasemonkey 0.8 or better which you can get here: http://www.greasespot.net/

Once you have Firefox with greasemonkey enabled, clicking install below should start up an Add-on installation dialog. If you just get to a page with a bunch of code, make sure your have the little monkey icon like this: on the bottom right of your Firefox browser.

Click on the button to install Urban Rivals Battle Calculator v0.1a
Or you can go to Urban Rivals Battle Calculator's Page on userscripts.org

If you are having any problems with the battle calculator or would like to request a feature to be added in future versions, let me know on the blog.

Uninstalling: It's easy to disable Urban Rivals Battle Calculator temporarily by clicking on the Monkey icon on the bottom right of your browser so it's grayed out. You can also permanetely uninstall Urban Rivals Battle Calculator by going to Tools>GreaseMonkey>Manage User Scripts. Then click on Urban Rivals Battle Calculator and then Click the uninstall button.

Basic Instructions

Once your have Urban Rivals Battle Calculator installed, go to Urban Rivals and click on play to go to the gaming area. Then it will look like the screen shot above.
The calculator in the middle is just your basic calculator with the standard buttons, including a Memory ("M") and recall ("R") button.
Once the battle starts, fill in the top section with your opponent's character's powers plus any attack bonuses they get. For example, a character with a power of 5 with the ability "+8 attack" would look like the picture on the right. Do they same on the bottom for your own characters.
Use the pillz box and plus/minus buttons to keep track of your opponent's and your own pills during the game.
Whenever a value changes in the game, and you copy the change over into the battle calculator (such as pillz being used up throughout the game) The MAX attack of a character will be reflected in their attack box.

SCREEN SHOT

Installing should like this if you have Greasemonkey running in Firefox properly:

Change History:

==ChangeLog==

v0.1 - May 5th, 2009
All new Tool Starting features are:
A top (opponent) pillz + character calculator
A bottom (self) pillz + character calculator
A middle basic calculator for figuring on-the-fly numbers