Turbo Power allows you to connect your ANT+ enabled phone to your existing bike speed/cadence sensors and, using known power curves, generate accurate power figures for your training sessions. In addition it logs all of your training data and allows you to upload it direct to Strava.
The app works in a similar way to popular applications like Trainer Road, Peripedal and Golden Cheetah, but since many phones have ANT+ built in it doesn't require any additional hardware.
During a training session, the app shows you your live power, speed and cadence as well as a graph of your whole session.
Free Version Restrictions:
Training sessions can only be recorded up to 10 minutes.
No Strava integration.
No TCX File export.
This app will only work if your device supports ANT+.
The power curves included in this app have been calculated by me from various sources and are likely to vary slightly from the actual.