Following the LibJBC for PS4 Homebrew Apps release and his recent PS4 Background Wave .FBXD Format Research, today PlayStation 4 Scene developer @0x199 made available via Twitter a utility dubbed PS4 IPI: Internal PKG Installer for installing PS4 PKG files from the HDD and through PS4 FTP clients like the OrbisFTP background app that supports all Firmware versions on Jailbroken PS4 Consoles. 
Download: IV0000-BREW00050_00-IPI0000000000000.pkg (6.31 MB) / GIT
Here’s further details from the README.md: ps4-ipi
PS4 IPI, short for Internal PKG Installer, is a PlayStation 4 utility homebrew app which will install PKG files from the HDD, making it possible to install PKG files using FTP.
It probably already exists in some way for PS4, but I mainly found this useful for myself so I decided to implement it.
Thanks to sleirsgoevy’s firmware escape the homebrew is firmware-agnostic and works on both HEN and Mira.
Usage
- Install the PKG onto your PS4;
- Enable FTP and upload the PKG you want to install to /data;
- Run the app.
IPI vs Debug Settings
IPI does have a disadvantage compared to Debug Settings. Because we’re uploading our PKG files now to the HDD instead of having it stored on a USB, the HDD requires 2x the space.
This is fine for small PKG installations, but if your PKG is very large, check with your system if you have enough space on the HDD x 2.
Credits
- flatz, for the bgft bonus code in his PKG installation writeup
- sleirsgoevy, for the extremely useful ps4-libjbc
- OSM, for PS4-Notify and the libjbc sprx implementation
- OpenOrbis, for the PS4 Toolchain
