To get the most out of iFile on iOS 9.3.5, you must first jailbreak your device. Jailbreak Tool
Install the package. If you encounter verification errors with repositories, you may need to install the ISRG Root X1 certificate via Safari first 2. Sideloading the IPA (Non-Jailbreak) You can sideload a version of iFile as an
file without a jailbreak, but it will be "sandboxed," meaning it can only see limited folders and files
Since the iFile servers are often down, the "Register" button may fail. Usually, the free version still allows 90% of features. To remove the pop-up, you may need to use a "License cracker" tweak from legacy repositories, though this is less stable.