Before Windows Phone 8: Update 2, when you downloaded an app or game or installed one from an SD card, a copy of the app installation file was stored on your phone, even if you uninstalled the app.
Bago ang Windows Phone 8: Update 2, kapag nag-download ka ng app o laro, o nag-install ng isa mula sa isang SD card, mag-iimbak sa telepono mo ng kopya ng file sa pag-install ng app, kahit na in-uninstall mo ang app.