You're on the right track here, but the app itself has nothing to do with it.
Usually this issue occurs when the iPhone was bought used or given by someone else. And usually when someone sells/gives away their iPhone they don't bother logging out of it or restoring it as new. So their Apple ID's will remain logged in, meaning that you will not be able to download anything until you log them out and log in with your own. To do this is really simple:
1. Go to Settings>iTunes and App Store
2. Click the email that you see (someone else's email in this case)
3. Click either "Delete Account" or "Log out" towards the bottom of the screen
4. Sign in with your own apple ID
If you do not have an apple ID then I recommend going to appleid.apple.com and creating one. Be sure that when you create it, your information is accurate and that you can easily remember both your password and security questions.