Name: vPower - Bike Virtual Power
Rating: 3.8 (137 reviews)
Author: vCorso

The vPower data field app has been developed for those who are not fortunate enough to own an expensive power meter. Firstly, this is not 100% accurate. As you can imagine, there is a lot of variables at play to calculate power on the pedals accurately. This is my best attempt to take all these variables into consideration and developed the app with the following key features:

Version History
1.0 - Initial release
1.1 - Corrected zero cadence check. So now there is no power shown if you are not pedaling. Applied smoothing of result. Power will display average of last 3 samples.
1.2 - Stability updates. Increased smoothing to 5 samples. Auto adjust size for different layouts.
1.2.2 - Stability updates. Crash should now be resolved.
1.3 - Updated for 1.1.3 SDK. Improved vertical power accuracy.
1.4 – Configurable options, Trainer support, Remove need for cadence. 
1.5 – Calculation updates for improved accuracy.
1.6 - Option to calculate w/kg, updated firmware for better device support.
1.7 - Cadence over 40 for power to calculate. Save field to FIT file.  Power max and avg in summary.
1.7.1 - Minor changes to fix FIT save & Strava upload issue (I hope)!
1.7.2 - Minor updates. Acceleration now part of formula.
1.8.0 - Support more devices. Averaging settings. Decimal fix for w/kg. Added a bunch of additional trainer support.
1.8.1 - Update issue with power spikes, and compiled for 2.4.2.
1.8.2 - Will now record power even when no cadence meter attached.
1.8.3 - Small fix to text for negative reading to avoid spike in FIT file (thanks Jan!).
1.9 - Re-look at all calculation to address power spikes.
1.9.1 - Improve power calculations (trying to base on actual power meter results). Added Feedback Omnium Over-Drive trainer support.
1.9.2 - Update for new Edge 830, 530, Forerunner 945 and MARQ.
1.9.3 - Added support for more devices and more indoor trainers (Jetblack Z1-Pro, Elite Fluid Elastogel (round unit), Elite Elastogel Force Mag 5 (3/5), Tacx Blue Motion (8/10)) 
1.9.4 - New trainer: Minoura B60 Remote 3/7, Kinetic Rock and Roll
2.0.0 - Major update in power calculation. Support for more devices like 130plus, Epix, Venu with addition of a few new trainers.

Configurable
-	Now supports the following options to be set to improve calculation accuracy:
o	Bike weight
o	Tyre rolling resistance coefficient (default set for Michelin ProRace 3)
o	Default ride position (Tops, Hoods, Drops or Triathlon)
o	Trainer mode (default is off). Set this mode if you want to get training power for the supported trainer.
o	Trainer – I only have a few at the moment, but will add as I get my hands on other trainer power curve formulas. If you have this, please send to me and I can add for you.
o	Calculation – Display calculation as watt, or w/kg.


General
- Data is saved to FIT file and can be viewed in GC.
- Power is calculated if you are moving (cadence must also be over 40). 
- Power consists of adding Vertical Power, Rolling Resistance, Drag & Air Resistance together to give total watts at a specific point in time.

------------------ Rate & Forum -----------------
Please rate my app if you like, that way I know if people like it. This will also help me stay motivated to build more apps. Also leave feedback if you have ideas on improving by joining the forum discussion: https://forums.garmin.com/developer/connect-iq/f/showcase/454/data-field-vpower---bike-virtual-power


------------------ Donate -----------------
Please donate if you feel the urge to do so. This will help me to be generous to others. I do not use this money for just myself, I have a day job for that. http://bit.ly/1M4uRlZ

Happy training!