SD card

[TkSilver]

Place the isos on your memory card.

All the saves, savestates, homebrew, dlc, screenshots and various other bits will be in internal memory bit the iso files for psp are far far far bigger like valkyria chronicles 3 being over 1GB. You do not need to be rooted to do this, but you may need to use a computer to access your memory card if your phone manufacturer was a certain kind of jerk and made saving al ost anything to SD in android 4.4 or higher more of a pain then it should be.

Btw: I run all my games besides the homebrew ones off of a samsung evo microSD card