Make that four.
Mine also works fine with the official Pebble app. No strangeness I can think of.
Official Pebble app provides me with caller ID, email, SMS, instant messaging(gTalk), calendar reminders, voicemail(Gvoice), Facebook, music and/or tts control. I have no idea about WhatsApp, I don't use it.
In addition to these, I also have Pebble Notifier installed for Google Now notifications such as traffic and ETA to home/work, navigation, and weather warning (though I have snow forecasts sent through IFTTT to SMS using the default Pebble app) and for whatever future apps I might install on my phone.