Everyone, of course, has seen a large number of iOS Data Recovery Services programs originally from China that promise to recover deleted files through DFU mode. Why do you say that these are fairy tales?
Take a close look at what exactly these tools restore. If you study their specifications, you will understand that they promise to restore only contacts, messages (including SMS, MMS and messages in chat programs), call histories, notes, calendars and reminders. What about everything else? (Vacation photos, for example).
All these tools can do is download existing files from the phone. The iOS operating system stores your contacts, call history, messages, calendars, reminders, and notes in regular files. Inside them are databases in the popular (and open) SQLite format.
Before we go any further, let’s take a look at what happens when you delete a message (contact or call record) from your iPhone. The system handles the deletion using the engine built into SQLite. Which, in turn, doesn’t immediately delete the entry (just like Windows doesn’t erase the file from the hard drive when you don’t delete it).
Instead, it notes that the database space has become free and places the deleted entry on the so-called “blank page list”. From that moment on, the recording becomes invisible and inaccessible to all standard instruments working through normal channels. So what do these tools actually do? They download call logs, message lists or contacts to a computer as SQLite Wikipedia data files.
Voila! This approach works for almost every type of information stored in a SQLite file, including all of the above, plus Skype history and chats, WhatsApp messages, and any other messenger that runs on your iPhone or iPad.