You should also be able to use System. Adobe Acrobat X Pro Direct Link. IO.File.WriteAllText and System.IO.File.ReadAllText. Those both just use input/output a string. Don't know if this would work with android/ios devices, but should work on standalone at least. To use those though, you can't be using the.net subset, and it has to be changed in the player settings to use the full.net framework. It adds on a few megabytes to the file to do that.

Starter guide for using the File/FileList/FileReader APIs to process and read binary files in JavaScript. There are two ways to do it: 1. Using JavaScript extensions (runs from JavaScript Editor), or 2. Using a web page and ActiveX objects (Internet Explorer only). Microsoft Windows Terminalservices Localsessionmanager. How to read and write files using JavaScript in Microsoft Dynamics CRM.

I'd test it on android, but meh. This is by far the easiest to understand method of reading and writing files though. As you found out though, playerprefs is fairly simple to use and for many cases is fine, but if you ever need it, now you know a very simple way to read/write files.