The first trick is to have a good software clear-out. Remove any apps that you no longer use. Apps take up storage space, and freeing up space makes it easier for iOS to operate.
Note that we’re talking about deleting the apps from the device entirely, not just closing them down (by double-tapping to open the multitasking bar, then swiping up on the app you want to close).
Deleting apps that you no longer use has a notable effect on iOS – especially if you have limited storage available because it will free up space.
You can delete apps you no longer want or use by pressing and holding on the app icon until it starts to jump around. Then tap on the x in the top right of the icon to delete it.
If you’re looking to delete multiple apps, there’s a quicker and easier way than deleting each one individually. Tap Settings > General > Storage & iCloud Usage. Now tap Manage Storage (under Storage, not iCloud) and look for items that are taking up lots of space. Podcasts, GarageBand and Movies are likely suspects. Tap an app to view its contents, and then tap Delete it remove it.
Here’s a guide to How to delete iPad apps.