PS4:App2USB

App2USB is a homebrew method to transfer and run games and applications to a external HDD. App2USB was originally developed and released when the latest exploited firmware was 4.05, and the official Extended Storage feature was added in firmware version 4.50. As a result, it functions differently from the official way (creating symbolic links, similar to having a shortcut on internal while having the content on external), having both some advantages and some disadvantages.

Some notable advantages over Extended Storage feature:
 * Uses a non-encrypted exFAT filesystem, meaning it can be read and written from any PC.
 * Supports any type of HDD or SSD, up to 8TB of maximum storage.
 * Is recognized by the PS4 as a USB drive, meaning it can be used alongside Extended Storage, adding a total of 16TB of external storage (8TB App2USB & 8TB Extended Storage).

Some notable disadvantages: '''
 * It is very buggy, can crash your system and can corrupt your USB.
 * Can only be used on exploited PS4s.
 * Requires the content (games and apps) to be first installed to the internal HDD, then to be moved to external storage.
 * '''Does not work in rest mode, can crash your system if sent to rest mode.

How to use app2USB

 * Install your content on internal HDD via Package Installer or Remote Package Installer or IPI etc.
 * Prepare your USB drive by formatting it as exFAT.
 * Download and copy app2usb.ini to the root of the USB drive.
 * Edit the app2usb according to your preferences. Each value has its description. By default, it will copy every single game and app (excluding system applications) to the USB drive. If you are fine with this, ignore it.
 * On your PS4, insert the USB drive.
 * Go to either a exploit host like Karo's and load app2USB payload or load app2USB via Payload Guest or send it from your PC using GoldHEN's Bin Loader feature.
 * Wait until you get the All Done notification.