In some cases, certain apps may be become slow or give you errors. In that case, it is a good idea to reinstall the app.
Warning! When you delete an app, its local data is permanently erased, including any saved documents, scores, or settings. Contact the developer of the app for more information.
1. Tap and hold the app you want to reinstall until it shakes. Tap the X icon in the upper right corner and then tap Delete.
2. Launch the App Store app, tap the profile icon and then tap the Purchased.
3. Tap Not On This iPad or iPhone at the top of the screen to see a list of apps you've uninstalled. You can also find the deleted app by searching the App Store.
4. Tap the cloud icon to the right of the app you want to reinstall.
5. If asked, enter your Apple ID and password to install the app.