User blog comment:Mrob27/Cursed Items/@comment-4501235-20111108201120/@comment-4583259-20111108235309

Scooter8pie:

Look on the Wikipedia page for ".ipa_(file_extension)". It says: "Files with the .ipa extension can be uncompressed by changing the extension to .zip and unzipping."

Find the file called "mooncraft 1.7.0.ipa". On a Mac in is in "Music/iTunes/Mobile Applications/mooncraft 1.7.0.ipa". Copy that file somewhere and call the copy "mooncraft-1.7.0.zip". Un-ZIP it. Then look inside the un-ZIP-ed contents for files called "items.txt", "itemscan.txt", and "recipes.txt".

This appears to be where the early info on this wiki and elsewhere came from. However, the presence of these files inside the app does not guarantee that these files are actually being used by the app (the programmer(s) might have decided to add new data in some other format, and left the TXT files around for no particular reason).