Yup, Whatsapp is a battery hog on Lumia 920. Apparently, for whatsapp to work in the background it needs to use audio streaming API. Only trusted developers would be given the access run the apps in the background. Whatsapp has no way to work around this but to use Audio streaming... I hate to know it, but unfortunately, I need whatsapp. So sort of living with battery drain for now... Without whatsapp my battery used to last more than a day... Now half a day.
I did another interesting test with Skype. It does work in the background, but unlike Whatsapp it uses push notifications. Skypes stores the users status online on its servers. As soon as it gets some activity for a particular user it uses the push notification to activate the Skype program on the phone. So Skype is not always connected to the server like Whatsapp. Unfortunately, it has other bug issues related to syncing the contacts which was the reason behind battery drain complaints. Interestingly, the idea of Skype's background functioning is good, but the way it is behind handled is riddled with many technical glitches like network connectivity and push notification server functionality...
Well, bottom line, WP 8 is no way close to Symbian in multi-tasking. I was under the opinion that once NT kernel is ported it would be good at handling multi tasking... but still it is the same as WP 7.5. A little better but needs a drastic change. In fact, I'm really pissed with its fast switching. Like I open an app, minimize it and open it again, it takes about 10-20 secs depending on the app type to open it on the screen... What kind of multi-tasking is this? Common MS you can do lot better. Especially, minimizing skype and open is so annoying as it tries to establish contact with server before it even shows you anything on the screen.
For now there is no good messenger for WP. Or I can say there is not efficient app or way to program an app to work in the background with minimal resources. Still wonder, if MS gonna come out with some API's to sort this out. Or Nokia just did a big gamble to let MS deal with all the software. As I'm still looking for half the functionality of my Symbian based phone I used 5 years ago now
I moved away from symbian for its clunkiness and UI, but functionality wise it was amazing. I need not reduce the volume of ringer to tone down my key pad dialer to begin with
Is MS getting all this I have no clue. But this not the way to build an ecosystem... Nothing is integrated and nothing works as promised. Where is the total integration with PC yet MS? Forget about instagram, atleast bring proper Skype. If MS cannot get Skype forget about bringing apps that can work in the background efficiently. End of rant... But MS seriously needs to listen. Or at least Nokia realizes to go with a different OS... If not for Nokia I wouldn't even had recommend this half baked OS to anyone... I'm just living with this agony.