Android applications one should have are-
1)Whats App : It is a messaging app which enables you to send free messages to the people who are there in your phone book and has whats app in their phone.
2)DU Battery Saver : It is an effective application which helps you to extend the battery life of your android phone. It solves the Android battery problem with the “Optimize” Button.
3)Tweeter : It helps to tweet and update your status.Features of this app includes photo sharing, link sharing, tweets, re-tweets and direct message to your followers.
4)Opera Mini : It is the fastest browser for the android mobile phones. It has a feature to open multiple tabs at the same time.
There are several other apps with different functions. It depends on user’s choice that which app he selects for his Android phone.