I rebuilt my unleashed network recently and had the same problem with getting the app to connect. The issue is related to DNS host unleashed.ruckuswireless.com not resolving properly. You can get around by finishing the unleashed network setup from a computer. Follow the below steps after the unleashed network is complete with the setup. (This is the process I went through to get mobile app access on firmware 200.7.10.202.118 on a pair of r500's).
1. open the app on your device and tap "manage network"
2. if you're logged into a social account then you need to log out by tap the 3 - at the top right and tapping "logout" and confirm with "yes" (You won't loose any other networks since its tied to your social account).
3. Tap "Change login destination ?" at the bottom right, just under the blue "Unleash" button.
4. Manually input the IP address or hostname of your access point and tap "Ok" (IP address will be easiest if you don't have an internal DNS resolver).
5. Input the admin username and password you used during the unleashed setup and tap "Unleash".
6. During the login process you will be prompted to continue or add to a social account, just use the same social account you have any other unleashed networks added to.