Looks really great man.
I think the clean angles and flat tones hold up to 3.0 well. As far as UI goes, the problem is finding a balance between stylized and readable, instantly recognizable. I'm looking at your home, login/out, and I don't know what the checkmark is.
Everyone is going to have their preferences but I would say with the other colors we've seen we could use a bit more orange. Something between what Indigo showed and what you have.
Even something rough like this, you instantly think "home". Simplicity is nice, but I see you using more than one tone on a few icons. I think it's a worthy tradeoff to have 2-3 tones and improve readability. If we were designing these for a client we'd want their users to know where to click at a glance, in an instant.
I think a monotone button could work as you have it, but individuality, usability is improved so much when you have another tone.
Is that a PM(offline) icon in the middle at the bottom? I would ditch the lock, it implies you can't perform that action. A better solution would be to take that same PM icon and grey it out a bit—message conveyed.
What are the tabs below the online/offline for?
Edit: Here are some more thought out ideas, keeping in with your theme.