A custom rom is needed to have removable apps. For zvd 2.2 froyo, reborn is likely the best, or a cyanogenmod rom like drew's or thekravens are good too. Or you could put in a little more work and update to zvh and there are a few good roms for it to !! You will need a custom recovery (xionia is the most commonly used as it works with all lcd versions of this phone) to flash any custom rom, and just make sure the rom is for the right radio version.