Demand for useing your cell phone as gps device for flying?

Hi,

being a private pilot since 2003 I always wanted to use gps for flying.
I learned flying in san diego in between of all these class bravo and
the mexico border. So before my solo x-country a got a e-trex which was
all right for the purpose. But after typing a set of waypoints into the
e-trex my fingertips began to hurt.
A year later I purchased a hp ipaq and a Bluetooth gps which I use for
car navigation, too. For flying I used ozi-explorer with scanned
sectional charts. Not to bad for flying, but while I get busy flying
it's hard to use the little pen and the sectional maps becoming hard
to read on the display.
A pilot friend showed me his garmin gps. I like the way of setting my
route by typing the letter-codes of airports, vor and other waypoints.
But since I'm flying just about 20h a year in my varation, it's
seems too expensive to me.
So being a software developer I tried to build my own solution. It's
a software written in .net wich makes it possible to use on any device
providing .net runtime. I got a new cell-phone wich is a windows mobile
phone. So I use a windows cell-phone, but it's also possible to use a
pda or a tablet pc.
The idea is: As a vfr pilot I plan my trips using the charts, draw my
route using waypoints. Then I type these waypoints into my cell phone a
have my route programmed. So I have two options: typing a letter code
(KSAN or OCN), or giving coordinates like in a e-trex). Setting a route
with about 5 to 10 waypoints is not big job.
While flying you get these informations:
- A display of your situation concerning your route in form of an HSI
display (your heading, your course as an arrow and your deviation).
- A Map view, where you see waypoints (airports, vor) and airspaces
around you.
- Numeric information about your position (coordinates), altitude and
groundspeed
When displaying an airfield, its not just a static symbol, you see the
runway directions and length four your situation awareness. When
displaying airspaces, these airspaces a displayed red when your alt is
in between the airspace altitude boundaries (very helpful in southern
california class bravo mess).

I used it in november and it worked for me. On sunny days it's
sometimes hard to see the details, but that's the same with pda
solutions.

Screenshots:
http://62.141.38.86/Snap002.jpg
http://62.141.38.86/Snap003.jpg

So I would like to read your opinions. Would you like to use such a
system?
Since I don't monitor the group often, please add my mailadress as cc:
ml2_lankenaus.de (replace _ with @)

I can provide a version for testing. You would need a windows mobile
2003 (or newer) cell phone and a Bluetooth gps. It's possible to try
the software with MS Flight Simulator. I used that feature for
development time.

To be honest, I'm planning to improve and sell the software, if I see
the demand is there. Price should be between 25-50$

Regards
Komischeszeichen