I’m quite surprised to see the data usage of the android app (2Gb /month). In fact it is the one with the very highest usage on my phone. Even more than e.g. YouTube our Netflix.
My usage of the app I consider not very high, each day I open it a few times to switch on our off a few lights.
I just started my billing cycle last week so I only have about 5 days worth of data, but in those five days Habdroid has use 28.15 KB. If I project that to 30 days I’m looking at around 171 KB for the month.
Do you have camera or video feeds on your sitemap? Is the app always running? I just don’t see how you get to 2.1 GB.
Come to think about it, I did encounter a bug last week with a colour light, maybe that caused high data consumption. (It got an invalid value and kept on updating)