How to choose a different simulator(other than iOS 8) in Xcode 6?. I have successfully installed the iOS 7 simulator from Xcode->Preference->Downloads
Also make sure your deployment target is set to at least <= 7.0 or else you'll only see the iOS 8 simulators
Once installed iOS 7 simulator, in Xcode 6 go Window > Devices, click on bottom left corner + button and add iOS 7 simulator. Then you can choose it in your Archive Scheme.