2. Is your idevice iOS up to date?
3. Have you tried exiting, closing and reentering the app? (Double click home button and swipe up to close)
4. Have you tried a hard reset of your device? Hold the upper sleep/wake button while also holding the home button until the screen turns black and the white Apple logo appears.
5. Try deleting and reinstalling the app from the Apple App Store.
6. Apple recommends you keep between 10-20% of your devices total memory "free" (unused) in order to ensure smooth functioning of the device and all apps contained within.