When we are doing some important operation or work on activity and it may possible that by mistake we pressed “back” button. Then what?? This will simply stop all your important work and you are redirect to previous activity.
If you are using NFC (Near Field Communication) Mifare in your application, you should be careful while using NFC Mifare UID
(Unique IDentification also know as Card Serial Number) of NFC card.
When I read this question http://stackoverflow.com/questions/8974088/how-to-create-a-resizable-rectangle-with-user-touch-events-on-android on StackOverFlow, I tried to develop a custom control overlay which behaves like it.
Read this article to make your own resizable rectangle overlay on touch in Android. This will help you in Image or map application.
Download Source : https://github.com/rathodchintan/rectangle-overlay
Following are words from http://proguard.sourceforge.net who are inventor of it.
ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. It renames the remaining classes, fields, and methods using short meaningless names.
Some time in your application, it is needed to prompt user before taking back him to previous page or exit from application. In this article, we will see how you can prompt user on pressing back button.