OptionsTrack is an application for iPhone running iOS 4.x software.

It is designed to track the value of a single stock over time, such as
an employee incentive stock option. 

It is based largely on worth.pl, written by Jamie Zawinski at 
http://www.jwz.org/hacks/worth.pl

As he says...

Do you hate your job? Are you only still there because you're waiting
to vest? I feel your pain, brother. The only thing that kept me from
leaving Netscape in 1997 and walking away from a dumptruck full of
cash in frustration was this script. I ran this every morning for at
least a year: it prints out the following motivational message:

Today's NSCP price is $__.__; your total unsold shares are worth $____. 
You are __._% vested, for a total of ____ vested unsold shares
($____). 

But if you quit today, you will walk away from $____.  
Hang in there, little trooper! Only _ years _ months _ days to go!

It's amazing how this script can put it all back into perspective and
keep you from going postal and strangling someone. Fill in your
numbers, and let it remind you not to do something you'll regret
later.