One can use the Easy Installer — a free android app — to install apps from the sdcard using the apk files already stored therein.
Easy Installer is a tool which can be used to install applications from SD card. It is the easiest and one of the fastest way of installing applications. It enlists all the Apk files on SD card and you can select the applications that you want to install. All that you need to do is select apps from the list and then click on ‘install selected Apps’ option to install the apps.
There is a search box on the top, where you can type the name of the app that you desire to install. There are options to sort applications into different categories.
If there is any problem with the SD card regarding installing apps, it is advised to clear the cache and scan the Apk files. This is expected to resolve the problem.
Following these simple steps you can download applications from SD cards on Android phones and tablets. The process can also be reversed if you want to save the downloaded applications on the SD card for the purpose of saving the internal memory of your phone.