I bought a Chi-knock-off OBDII bluetooth adapter from Amazon for ~$25 and tried it with Torque (free) on my Motorola Droid 1... it worked so I paid for Torque (4.99). This combo has worked on my wife's Toyota Avalon and my '03 Chevy Astro work van so far, haven't tried it on a Ford yet, but I suspect it's not going to work well with the J1850 protocol. Also, I get occasional broken connection to BT adapter, and "faulty obd adapter" message in Torque while using it to monitor in real-time. But it read and cleared a CEL on the Astro van just fine.
Don't bother with the ~$45-50 ones from ebay or Amazon, they're the same as the ~$25-30 ones, just re-packaged and re-labelled.
Higher quality bluetooth OBDII adapters:
Kiwi Bluetooth $100 MSRP, ~95 on Amazon, gets good reviews, on/off switch.
Scantool.net Bluetooth $150, the best of the lot, fastest refresh rate for real-time monitoring of sensors. 3 year warranty, 90 days no questions return, also has USB port for laptop use, upgradeable firmware, extended command set, premium software available, on/off switch.
BTW... all these "calculate" horsepower, torque, MPG, etc... based on your inputting vehicle weight and engine displacement.
The Scantool is the one I'm saving up for...