Apple is a walled garden with the intention to force use of their tools and platform at all stages. It is unintentionally hostile to the maximum to keep the world Apple.
You can work around this to a very limited extent by making web applications that work in the browser. There are still limitations in that Apple disables some browser APIs for iOS, for example some parts of the file system API. There are also some artificial memory limitations in the browser that will prevent processing large data in one step.
In my case these limitations exist so that people use the App Store and if Apple blocks solutions from the App Store then they want you to use iTunes. Here is what I had to do to build something that works on an iPhone that Apple goes way out of the way to block.
I was wanting something like WinAmp for playing music from files I have locally from a large playlist. Even solutions that cost money from the App Store were garbage with regard to playlists and were often filled with ads and spyware. So I wrote a local web page that solved this problem.
Because Apple blocks some use of the file system API the playlist has to be dynamically assembled on the server. Because it’s to large to parse in a single step the browser has to request the playlist data from the server in 9 different requests. It works well allowing the playing of audio in MP3 format directly from the browser in the way I want without paying Apple or streaming from the internet.
That is the level you have to go to for working around the Apple profit garden.
