Delete unnecessary applications.
Apple 13 applications may take up a lot of memory space. If you don't use an application often, you'd better delete it. To delete an application, long press the application icon, and then click Delete Application. If you need to reinstall the application, you can find it in the AppStore and download it again.
Clean up Safari browser cache
When browsing the web with Safari browser, the browser will cache some data to improve the browsing speed. However, these cached data will take up a lot of memory space. To clear the Safari browser cache, open the Settings application and click Safari Options. In the advanced drop-down menu, click Site Data, and then click the Delete All Site Data button.
Clean up the application cache
Application cache is some data stored in the memory of mobile phone, which is used to improve the running speed of applications. However, these cached data will also take up a lot of memory space. To clean up the application cache, open the Settings application and click General Options. In the "iPhone Storage" drop-down menu, you will see a list of all applications. Click the application whose cache you want to clear, and then click the Clear Cache button.