See README.md on the GitHub https://github.com/ryomuk/emu8080on4004

It  is written mostly in Japanese. If necessary, please use a translation service such as DeepL (I recommend this) or Google.

Calculator (written in native 4004 assembler)

VTL interpreter (written in native 4004 assembler)
Palo Alto Tiny BASIC (running on the 8080 emulator)
Grant Searle's 8K BASIC (ported to 8080) (running on 8080 emulator)