Please refer to this link if you are Downloading an app for the first time .
To Un-install an application from your Kindle Fire:
You can remove an app from your Kindle Fire device, or you can delete it from your Amazon.com account. Apps removed from your Kindle Fire device are stored in Your Apps and can be downloaded again from your Cloud Library. If you delete an app from your account, you'll have to purchase the app again to re-install it on your Kindle Fire.
To remove an app from your Kindle Fire device:
- Tap Apps from the Kindle Fire Home screen and then tap Device.
- Press and hold the app you'd like to remove and tap Remove from Device.
To permanently remove an app from your Amazon.com account:
- Visit Your Apps from a web browser.
- Select "Delete this app" from the "Actions..." drop down menu to the right of the app.
- Then remove the app from the Kindle Fire Apps Library Device tab.
To Download the application to your Kindle Fire again:
You can download apps previously purchased from Amazon Appstore for Android as long as the app is available on Kindle Fire. To find and download previously purchased apps available on Kindle Fire:
- Tap Apps from your Kindle Fire home screen and select Cloud.
- Long-press (press and hold) the app you'd like to download and select Install.