The 7zip under Windows gives the choice of encrypting the ZIP file with the regular ZIP encryption or with AES-256 encryption. 7zipper for Android doesn't seem to give a choice. Which encrypton does it use?
The application doesn't use an encryption module at all. It allows you to do the base operations and that's all. There is no encrypt option or module available within the application. Bottom line, you can't encrypt files on Android with 7Zipper.