If you’re looking for a way to easily install third party apps off of your memory card, there are currently two options available to you. Those two apps are Apk Installer and AppsInstaller. Both will provide you with the same end result of having installed the app from your memory card, but each one has a slightly different user interface.
Apk Installer feels like a full file manager more than anything else. Unfortunately you can’t manage your files like you would be able to if that were actually the case. This can be rather frustrating seeing as you can navigate through quite a bit in this app but have to manually find your apps and install them. It also provides a link to download third party apps, but it’s for Android123 which is not in English.
AppsInstaller on the other hand searches your memory card to find all the third party apk files located on there and lists them out for you. No extra features needed as this is clearly only to be used for installing apps directly from your memory card. There is only an About button if you press menu as well.
Sizing both of these apps up leaves AppsInstaller as the clear victor. It is much easier to use and provides exactly what it says it will with no issues. This app was also made by the people over at ModMyGphone which shows you exactly how easy it is for a community to band together and make exactly what they need. If you need an Apk installer, download AppsInstaller.