It looks like YouTube for iOS & Google+ are not cooperating with many users right now. 

Signing into YouTube greets me with a weird “authenticating” error…

…while Google+ just crashes. 

So far those are the only Google apps I’m having trouble with (Gmail, Chrome, Blogger & Google Voice are fine but I’m hearing reports about trouble with the latter now). 
I do not rely heavily upon Google as I use to, but for those who do I feel your pain! Kind of…