You should make sure you are keeping your apps updated. App developers are constantly adding new features of fixing bugs and you should make sure you have the latest version of your apps to prevent your apps from potentially stop working properly. There are two ways to keep your apps up to date: manually and automatically.
If you would like to have your apps be updated automatically, from your Settings app you can select to have your apps update automatically by moving the switch to green.
If you would like to manually update your apps, open the App Store app and at the bottom. press the Updates icon. If there are updates available, you can press the Update all button or update your apps one by one.