Sorry, I wasn't very clear. For item and level names a hex editor is not necessarily needed, but to do anything else like editing mob names and code, or to change the length of item or level names you will need to edit text files in a hex editor. I don't know why, but a regular text editor will corrupt some files.
From memory, the apps I used in tutorials were just an APK editor, an APK signer, a hex editor, a file browser and a base converter (hex calculator). If you managed to make a successful mod already then you should have pretty much everything. You can find plenty of hex editors for windows, like 010 editor, and there are many base converters online.
I'm sorry if I'm still not fully understanding the question.
