How to extract apk file inside's font file?

I make a android game with unity and apk file generated.

I opened with unzip program, and it only shows folders and files like,


game.apk
-assets
–bin
—Data
sharedassets0.assets.split0
sharedassets0.assets.split1
sharedassets0.assets.split10
sharedassets0.assets.split100

Normally, I can’t see or find my used asset files, fonts, images.

But someone did.

How to do it?

What program he used?

maybe something like this?
https://7daystodie.com/forums/showthread.php?22675-Unity-Assets-Bundle-Extractor
or
http://zenhax.com/viewtopic.php?t=36
(Did not test any of this tools)