Bills is a folder that provides a convenient environment to enter amounts and have them collected and summed up.
Use is very simple: you slip into the folder, enter your amounts and tap done when done.
Bills automatically saves the current stack for you as you enter the folder and switches to right-aligned, 2-digits after the point fixed number display. You're encouraged to flick through the stack when you entered all amounts to ensure they're correct. As you exit the folder, your previous stack is restored.
Here's a sample session:
As you enter the folder the stack is cleared.
Enter some amounts, then switch to full-screen to check them.
Note, a variable, "last", is created which stores the two result lines.
If you want to keep a permanent record of this, rename "last" to something like "Skiing Bills Dec 2010", or email your stack with a tap on "email".
Exit Bills and see your previous stack.
That's it. A simple, but hopefully useful tool.