MobileGTD uses simple text files for projects. Each line in a project file can be either an action or an info. When adding an action to a project, a new line is added to the project file and a file is created in a directory structure corresponding to your contexts. If you e.g. create an action "Computer Download new version of MobileGTD" MobileGTD will create a file "Download new version of MobileGTD.act" in a directory called "Computer/". You can also use nested contexts, e.g. "Computer/Online/" to further structur your contexts. To avoid too much typing you can define abbreviations for contexts, you could e.g. define "26" to be expanded to "Computer/Online/".
Python for s60 is required to run this app.