I have a Nexus 6P. I have disabled battery optimization for a few apps and yet those apps still seem to doze off.
Specifically those apps are 1) a sip client (csipsimple and bria) and 2) pushover.
It would be great if those apps would never sleep :-)
Is this possible?
Edit: I agree with CmosBattery below that this might not be the way to go. In fact, I have set battery optimization on all apps like it was before. As mentioned in my comment below, some apps, like Bria, suggest that we should do so (and maybe they shouldn't suggest this at all). After a few weeks with the suggested setting, I see no improvement in call reception and a reduction in battery life.
GCM allows developers to send high priority messages. High priority messages allow you to wake your app (haven't tested, but the Android documentation says that this is reliable). Could there be other ways?