Once you enable push notification, you'll see in your asterisk log that your SIP account is registered every 10 minutes from this UA:
18.104.22.168 UDP Acrobits SIPIS (http://www.acrobits.cz)
Even after I uninstalled Acrobits 4.02, this UA is still registering with my SIP account. I searched, but could not find a way to remove this. I had to change my password for this SIP account to get rid of this.
This is truly stupid. Push is supposed to save battery so your phone does not have to be awake to wait for income calls. However, Acrobits still keep your phone awake all the time, ever since V2.0. What's the point to push? Just to hijack my account without offering a way to opt out?