If you purchase a new iPhone or iPad, or a new Android phone or tablet, and are an existing subscriber to this app, you can continue your subscription without interruption. You can also run the app on multiple devices tied to the same iTunes/App Store or Google Play Store account.
The devices must be tied to the same account. A single subscription cannot currently be shared across Android and iOS devices, as they are sold through different stores to different accounts.
Simply tap the "Enable This Device" link on the "Subscribe" screen (which you can find by tapping either the "Search" or "Picks" icon) and enter your store email/username and password. You'll instantly gain access to wine ratings without needing to re-subscribe.