The insanely addictive Smartphone game is now available for your hacked PSP. A bit of caution though, Flappy Bird is extremely fun (and equally hard) on the PSP.
Please ensure that you have a hacked PSP before proceeding further. Check out How to Hack your PSP if your PSP isnt hacked yet.
First of all Download Flappy Bird for PSP
This will give you a .zip file. Extract it using WinRAR or 7zip or whatever extracting software you have.
Now plug in your PSP by USB.
Navigate to /PSP/GAME/ and paste the FB and _MACOSX folders there. That should be it, now you can play Flappy Bird from your PSP, just navigate to Games-Memory Stick from your PSP Main menu!