The Android OS comes with a range of great built-in applications. The Google suite (Gmail, Maps, Market, Search, Youtube etc) is marvelous. Manufacturers also design their own built-in apps, making Android handsets even smarter.
There are already so many web sites that talks about the 10, 25 or 100 must-have Android apps. Let me take a slightly different approach. If I am allowed to download and install only three apps from Market, what would they be?
The first app that I would install is a File Manager. Some but not all manufacturers have pre-installed file manager into their product. Having a file manager makes finding, copying and pasting files on phone memory and SD card much easier. There are many free file managers available on Market. Install,explore and choose one that suits you best.
The second app that I would install is a Task Manager. They are also referred as Task Killers. This application is particular important if the specification of your Android phone is mid-low tier. If your phone often gets really slow, if it sometimes does not respond to your clicks, if you see "android.process error"; it's time to install a Task Manager and "kill" the apps that are not in use.
The third must-have app is a game like Jewels. Apart from being a fun game to play with, it is also a useful application for testing the responsiveness of your phone. You will touch and drag on almost every corner of the screen when you play. And because there is a time limit on each game, your fingers tend to swipe faster than usual. You will be able tell how good your phone is after a few games. Compare by installing the same game on another phone.
I believe these three apps can simplify your life. Enjoy Android.