First, Force Close the app, Try powering off your device, and then turning it back on again. (For iOS users, press and hold the button at the top of your device, until the "Power Off" slider appears on the screen, and slide it to the right.) Wait for the device to shut down completely, and then turn it back on.
If you are unable to work out a solution, Please contact our support team at smurfs.zendesk.com and share a detailed description of the issue, screenshots, device info and OS version so that our team can help you fix it.