Since there is no "official" Android port of the original Save Builder, users typically use these methods to get "full" save management: How to import PS2 Save Files AetherSX2 - Android
The interface was brutally technical. Raw hex dumps. Block lists. Checksums. A normal person would run screaming. But Marco had spent the last six months learning MIPS assembly code just for this moment.
Assuming you have obtained a legitimate full-version APK or app from a trusted developer.