I'm having the same problem with my 650 2ch. As soon as I upgrade the firmware to v2.0 the wifi doesn't connect with the app. I emailed pittasoft about this issue, they said the app update is coming soon. For now I'll try to downgrade to V1.009.
So I downgrade to v1.009 and the wifi is working again. This way you have the luxury to view the footage through your phone and download them. I can stay with v2.000 but you have to extract the footage through your computer and I have some videos that won't play. Pittasoft have confirmed the update for the app new version will be this week. I hope.