The search for "Modern Combat 4 PPSSPP" is a nostalgic cry for the golden age of mobile shooters. While the technical reality is disappointing (the game isn't on PSP), the solution is rewarding. You have two paths:
I notice you’re asking about on PPSSPP (the PSP emulator). modern combat 4 ppsspp
Don't let the clickbait YouTube titles fool you. Use this guide to actually play great shooters on your phone today. The search for "Modern Combat 4 PPSSPP" is
: While it has been removed from some official stores due to age and compatibility issues, players still use APK and OBB files to install it on modern Android devices. Don't let the clickbait YouTube titles fool you
What you are likely finding are fan-made ports or mods. The modding community has a history of taking popular Android games and converting them into ISO formats that run on PPSSPP. These versions are often stripped-down adaptations of the PC or Android versions, optimized to run within the PSP emulator environment.