If you use iOS 8 and have been experiencing issues, please try the following and let me know how it goes:
1) Update to iOS 8.0.2 - You can do this by going to Settings.app and choosing "General" and then "Software Update". You'll want to select "Download and Install".
2.) Delete and reinstall SongPop. Here are the instructions for how to delete and reinstall SongPop:
Touch and hold the SongPop icon on the Home screen until the icons start to jiggle.
Tap the "x" in the corner of the SongPop.app.
Tap Delete to remove the SongPop.app from your device. You will not lose any progress or data by doing this, as all of this is stored on our servers, not on your device. Just be sure you know your SongPop login information: your email address and password.
Click the Home button to cancel or stop deleting apps.
Once you've done this, you can then select "AppStore.app" and search for SongPop. Then you will be able to download and install SongPop again. If you have SongPop Plus, you will NOT be charged again to reinstall SongPop as long as you use the same login for the AppStore that you used when you purchased SongPop initially.
You'll be prompted to login when you launch SongPop after reinstalling it. Select "Log In" (already have an account) Enter in the email address you use for SongPop, and then your SongPop password.
3.) Please do let me know how it goes. I'm here to help!
Jess - your SongPop Support