My name is***** am sorry to hear that you are having this issue.
I will be glad to assist you with this.
Do you see an app in your app list that is blue with a picture of a bell?
See image in blue link below>
You can reply to me here by typing in the box below please
Kindle Fire libraries are where you access downloaded content, as well as content stored by Amazon in the Cloud.
Tap the apps library button to open a library of downloaded Apps. Let me know if you see it there.
If it is not listed let me know if you installed the app directly from the Kindle or from the Amazon on your computer.
Okay, try this to install the app please.
you can go to the appstore link on your kindle and choose download or install, make sure that you choose the correct kindle to receive the download.https://play.google.com/store/apps/details?id=com.ringapp&hl=en
okay, I will open this back up to the other experts.
Thank you for your patience.