Pokemon GO On Apple Watch Will Drain Both Watch & iPhone
The only reason why people would want to run their Pokemon Go app on the Apple Watch is so that they can put their phone to sleep and conserve whatever battery they have until a Pokemon appears.
However, it has been reported that the Pokemon Go on the Apple Watch will work just like the Pokemon Go Plus which means you will still need to have the Pokemon Go app running in the foreground.
That makes the app completely useless. You won’t have to keep staring at your phone now as you can wait for the Apple Watch app to notify you of a Pokemon nearby but your battery will still be drained and since you will be running it on your Apple Watch as well, you Apple Watch will also be running out of battery fast.
You also won’t be able to catch Pokemon with the Pokemon GO App on Apple Watch.