I have the newest ios 7.0.2. and the newest update on snap chat but ever since I updated the app, the app just keeps on force closing, please help!!

You need to contact the support desk for Snapchat

Another thing you can try in do a uninstall of the app. Then do a complete reinstall and see if it works again.

If you go the apps website, does it say they've updated it to be compatible with the new iOS update?