To install apps on Android phone you have to go to Android Marketplace, search for required app, proceed to download and installation procedure. You do not have to do that always. Because Android Marketplace is not the only source to get Android apps. There are other easy ways to get the apps on your Android. For example you can visit Android developer’s sites to download Android apps. Normally they have associated Barcode or QR code to facilitate the downloading. Here is how you can install apps on Android phone through its camera by scanning barcode.
Many android apps do not make it to Android marketplace. Still those are released by android developers in APK format and called off-market apps. To install a non-market app on Android phone follow the instructions below.