Are you looking for this:
|AirPlay (double press on Home button then swipe twice to the right on Multitasking Bar)|
|iOS Remote App|
and not seeing one or either of these features on your iOS device?
If you know how and are able, try changing the Channel setting on your router. This is what works for me! This is a screen shot of what it looks like on my Linksys router. Yours may or may not be similar but you're looking for this general area.
I posted this in part as a reminder to myself for figuring out how to fix this problem, but I thought you might find it useful as well. Let me know if it works for you.
The question I still have is why I need to keep changing this setting from time to time. I believe it has something to do with the fact that I now have more neighbors with routers and the channels are experiencing some kind of traffic or compromise. I don't yet know how else to explain it. One of these days I'd like to take a networking class because this stuff fascinates me. I wish I could fully understand all the ins and outs of my own router. For now, this is what I am comfortable tinkering with when it comes to my router settings and fixing the problem even if it's only temporary.