Signing your app before publishing to Google Play or Nook

                 Now your android application is ready and passed all tests. You surely want your application to go public. So you will publish it to android markets like Google Play,Amazon or Nook.

                 Before publishing the app to Google play or Nook you have to sign the app with your own keystore. So here we will discuss, how to make the keystore and then sign your app. Please note that currently to publish in amazon app market it is not mandatory to sign the app with your private keystore. But it is best practice to sign your app with your private keystore.

                The keystore data is needed when you wish to upgrade your app. Your application package can be signed with only one keystore. After publishing you can not sign the same package with different keystore. In that case if you wish to publish an upgrade, users get it as a new app,not an update.So, you should publish your app and its upgrades by signing with same keystore.

                So let us show how to make the keystore and then sign your app. We assume you are using eclipse IDE with ADT plugin for development. So select your project,then go to file and then export.

1st screenshot

          Now you will see a window like this. Here you press android to make it expand and then Export Android Application and after that hit next. Then another window will open like below image.

2nd screenshot

Here hit browse and select your project and after that next. You will get another window.

3rd screenshot

         Here select Create new Keystore. Then click browse to select a location to save your keystore and also give a name to your keystore. Then fill the password fields. The passwords must be greater or equal to six characters. This password is needed to access your private keystore for a later time. So you have to remember it. After then hit next and you will get the window to store keystore values.

4th screenshot

         Here you will see a form with different fields. Here first four fields are mandatory and you have to fill at least one field from the rest fields.You can of course fill all the fields.
         Alias name- here you can fill with any name your project specific that you can recognize in future. Here the password is your private key password. For security reason it is advisable to make this password different from your keystore access password.Now fill the rest of the fields(optional, but at least one is mandatory) and then hit next. Her your keystore is ready to use. Now you will get another window.

5th screenshot

         Here you will sign your apk with the keystore you just created. So hit the browse button and select a location where you will save your signed apk and give your .apk file a name and after that press finish.Now you will have the signed .apk ready to publish.

         If you have an existing keystore for your app's older version, then just  select use existing keystore(see third screenshot). After that key your keystore access password and your keystore private key password on by one. You will get the window like fifth screenshot. Then just sign the .apk following the above steps.