Version 3.4.0 seems to use the location service a lot and drains my battery very quickly. I think this started with Google Play Services 7.0.97, but I cannot say for sure. Switching to a manually entered location stops the battery drain. HTC one M8 on Sense 6.0 and Android 5.0.1.
I noticed this under Settings->Location->Recent location requesta. WatchMaker was listed as High Battery Use, until I switched to manual location mode.