was never released for the PlayStation Portable (PSP). It was developed exclusively for the PlayStation 4 (and later ported to PC). Therefore, no PPSSPP ISO file for Uncharted 4 exists — because PPSSPP is a PSP emulator, and the game was never made for that system.
Uncharted 4: A Thief's End is a PS4 exclusive game, and it's not officially available for Android or PSP. However, some gamers have been experimenting with running PS4 games on PCSX2, a PS2 emulator, and then porting it to Android using PPSPP. While Uncharted 4 is not natively supported on PPSPP, some developers have created custom ISO files that can be used to run the game on Android devices.
No mainline Uncharted game (1, 2, 3, or 4) was ever released for PSP.
The answer to this question is a bit complicated. Uncharted 4: A Thief's End was not officially released for PSP or Android, so there is no official ISO file available for download. However, some websites claim to offer Uncharted 4 PPSPP ISO downloads for Android free. We must emphasize that downloading games from unauthorized sources can be risky and potentially illegal.
Any website offering a “Uncharted 4 PPSSPP ISO” is almost certainly: