Currently, if you purchased SwiftKey Tablet from Google Play, you will be able to access updates. Log into the store with the account you used to purchase, go to "My Apps", and you will see an app called “SwiftKey Tablet (Legacy)”. Updating to this app will give you all of the functionality of the combined SwiftKey (phone+tablet) app.
If you have also purchased SwiftKey we recommend that you simply install SwiftKey on all your devices and then uninstall SwiftKey Tablet. You can use SwiftKey Cloud to ensure that your learned language is transferred.
If you purchased SwiftKey Tablet from the Amazon Appstore or AndroidPIT, please contact their customer support teams at www.amazon.com/appstore-support or http://www.androidpit.com/faq to request that your purchase be transferred to the main SwiftKey app.