Have you noticed your iPhone response slower and slower? Or have you ever received the warning just as the picture shows? All these indicate that it's high time that you cleaned up unnecessary data (refer to cookies, caches, temporary files and the like that take up much storage space) on your iPhone.
As we all know, it's not that easy for us to completely clean iPhone unnecessary data since iPhone is extremely good at keeping data. So here I'd like to introduce a powerful iOS 10/9/8 cleanup tool: iCareFone (iPhone Care Pro), with which you can easily and entirely clear iPhone unnecessary data. It not only supports iPhone SE/6S Plus/6S/6 Plus/6/5S/5C/5/4S but all iPad/iPod as well. In addition to that, you can also use iCareFone (iPhone Care Pro) to remove in-app ads, fix stuck issues, backup and restore your data!
Generally speaking, iCareFone (iPhone Care Pro) enables you to remove up to 5 kinds of iPhone junk files. But before following the detailed instruction below, you must download and install this professional iOS cleaner to your PC first.
Note that with files manager you can delete iPhone files much more thoroughly than you do directly on iPhone, since nowadays there're many iPhone data recovery software helping to recover deleted iPhone messages, contacts and the like. For your privacy, iCareFone( iPhone Care Pro) is highly recommended here.
After this being done, your iPhone would run much more smoothly and have enough space for updating to iOS 10/9/8. In case your iPhone freezes up during iOS 10/9/8 update, you can read Top 3 Tricks to Fix iOS 8 Update Freezing Issue on iPhone first.