There are many people now use iphone, send apple end OBD-II Software for reference,
OBD-II data terminal interface to read, you can use Bluetooth, you can also use USB, Bluetooth personally believe that there is a delay, USB connected laptop should be better. Bluetooth is a "Bluetooth ELM327", USB is the "ELM327 USB OBD2",
Interested can go here to find:
http://www.obdchina.com/vgate-bluetooth ... 300ecuedit

Description
WANT GAUGES? It's an app for that. DashCommand is the ultimate OBD-II vehicle Additional Tools available for the iPhone and IPod Touch. Built in the panel can display a total of 27 gauges pulling data directly from the Engine Control Module in your trip. In addition, the use DashCommand as scan tool to read and clear trouble codes that caused the "Check Engine Light" to start, trip computer, or a race day companion.

NOTE: DashCommand requires a compatible interface hardware, sold separately, see below.

--- SEMA Show 2009 1st runner-up for best mobile electronics products.
--- Winner of 9 Global Awards media at SEMA Show 2009

Get the benefit of multiple gauges without the overwhelming clutter and the expense!

Performance gauges:
- Engine speed
- Fixed vehicle speed
- Open / closed loop *
- Boost / Vacuum Gauge Combo
- Acceleration (and deceleration)
- Power with an additional correction of resistance (air and bus) **
- Torque **

Sensors Fuel Economy:
-. Inst Fuel economy ***
- Average Fuel Economy ***
- The average fuel economy over 3 time periods ***
- The distance to empty *
- Time empty *
- The fuel level% *
- Fuel remaining in the tank *
- Fuel Gauge

Engine sensors:
- Timing (spark advance) *
- The engine coolant temperature *.
- The air supply rate.
- The room temperature *.
- Manifold Absolute Pressure
- Mass air flow
- Fuel trims, short and long term *
- The percentage of engine load *
- Catalyst Temp *.
- Fuel pressure *
- Lambda gauge *
- The ratio of the air / fuel ratio *

* Requires that the vehicle supports the underlying parameter.
** Requires car setup values.
*** The fuel economy for diesel vehicles is experimental and may require more time to calibrate

DashCommand also contains a sophisticated trip computer that maintains 41 stats for 5 trips, custom and B trips, Today, Yesterday and Fillup.
- Distance traveled
- Fuel Consumption
- Average Fuel Economy
- The cost of fuel
- Elapsed time
- Time
- Average rate of carbon dioxide emissions
- Total emissions of carbon dioxide
- Start date and time
- The number of fillups
- Average Fuel Consumption
- Average speed
- Average speed of travel
- Average gain / Vacuum
- The average speed of the motor
- Maximum acceleration
- Maximum engine power to the wheels
- Number of stops
- Maximum fuel flow
- Maximum speed
- Downtime
- The maximum boost / vacuum
- Maximum engine speed
- Maximum acceleration deceleration
- The maximum torque of the engine
-% Distance, and not in the transmission
-% To the distance traveled in each gear
-% Distance in less than optimal gear
- Time spent% while not transferring
- Time spent on each transfer%
- Time spent% while in suboptimal Transmission


Additional features:

- Professional Skidpad showing lateral and accel / braking Gs with min / max indicators
- Race track visually displays your location, acceleration and braking as you drive laps around the track allows you to visually analyze different race track laps to see how acceleration and braking changed from lap to lap thus helping you improve your lap times on your next outing.
- Inclinometer shows the angle of the car and move to off-road.
- Full support for OBD-II diagnostics, find out why your check engine light is on and clear diagnostic trouble codes (DTC)
- Data logging, record and playback log files showing OBD-II data and Skidpad / race track data simultaneously

-----------------------------------

Caution: DashCommand requires the purchase of a compatible third party hardware interface to communicate with the vehicle OBD-II port Skidpad, race track, and inclinometer not require OBD-II data and are fully functional without any extra hardware with iPhone .. GPS is required to display the race track.

DashCommand supports all OBD-II and EOBD compliant vehicles sold worldwide.

Hardware compatibility:
- ELM compatible Wi-Fi (OBDLink, PLX Kiwi Wifi + iMFD, OBDKey WLAN)
- Innovate Motorsports OT-2
- GoPoint Technology GoLink


What's New in Version 2.6.0
+ Added Ipad / Universal support
+ Fixed a problem of slow play on iPhone 4
+ Increased the connection timeout for ELM interfaces Wi-Fi
+ Updated icons and screensavers
+ Fixed boot hangs when booting from DashXL.net

Thank you very much for sharing this information, best regards.

I bought Dash Command for the iPhone and PLX cable from Greece and it's really only good for reading and clearing codes. You can't do all the ECU tuning stuff with it.