If your issue is that they're closing right after you open them then it's a common problem across all phones that supposed to be fixed in tomorrows update. You can fix them right now by synchronizing all your apps with iTunes. Then, uncheck synchronize-apps and click Apply. Then, check synchronize apps again and all your apps should be working again.
is the issue when you open it it just has the loader circle and doesnt load, or it just freezes, if so, to exit hold down home for as long as needed, up to 20 seconds. and with my advice, buy apps on ur computer and sync them