How to know if my iPhone 4s is fully charged running iOS 7?

I just downloaded iOS 7 and for about an hour, maybe more its been showing that my phone is on 100% and next to the battery it's the lighting, in iOS 6 it used to show a charging plug when it was fully charged. I know that when its 100% charged its fully charged but its supposed to show a charging plug, what should i do? Once again i have and apple iphone 4s.

Apple confirmed that it will no longer have the fully charged indicator which was the (charging plug) from now on it'll just say its 100% charged:(

In iOS 7 they got rid of that icon. When it hits 100% it is now fully charged. It only takes a few minutes to go from 100% to that full charge capacity you recognize in iOS 6. Performance is minimal and batteries are better off unplugged when they are fully charged.