I'm fairly new to iOS development and I upgraded my device to iOS 9.0 beta, to see how my app faired. However, I did not upgrade to Xcode 7 beta. I'm getting an error that says my device is now "ineligible", specifically,
iPhone (3) may be running a version of iOS that is not supported by this version of Xcode.
Is this standard? Do I have to upgrade to Xcode 7 if I'm running iOS 9.0?
Yes, you need to install Xcode 7 in order to develop for iOS 9. You are able to keep Xcode 6 running alongside Xcode 7.