Some of Android apps ( strava,ipbike) have possibility to show Power in Watt in Dashboard just like speed , heartrate, cadence etc..
I think many people will be interested to have this possibility in Locus.
Most popular is Power through ANT+ but possible also via BLE (Bluetooth 4.0) or just by mathematical algorythme .
About Algorythme I dont know which alghorytme is the best .
Some of them taking into account speed, cadence, road gradient,weight of cyclist or bike but they are also formulas according to heart rate and calories .
The simplest one Power=1,25*Weight of Rider*9,81 (Speed*road gradient)/ 360
Some interesting sites regarding calculation without sensor https://strava.zendesk.com/entries/20959332-power-calculations
It is not so useful on flat becouse for ex. of wind factor but quite good when we climb hills. Last summer my heartrate belt callapse and i have made few ride looking instead at ,,power'' on my Rox 10. And it really help.
I dont think difference with ''real power'' is very big.