We encourage you to support the developers. However, for users with legacy hardware who cannot run the Definitive Edition, the PPSSPP emulation route is the only viable path.
You cannot run a PSP game directly on Android or PC without an emulator. (created by Henrik Rydgård) is the gold standard. Here is why you want this setup:
Most of these ultra-small downloads (like the 70MB versions) are heavily compressed "modded" versions of other GTA PSP games, such as Liberty City Stories or Vice City Stories
Caution is advised when searching for a download of Grand Theft Auto: San Andreas