櫻坂46メッセージ is a lifestyle app developed by Sony Music Solutions Inc. It is available for iPhone users and can be downloaded for free. The app allows fans to subscribe to their favorite members and receive exclusive messages, including text, photos, and videos that can only be accessed through the app.

One of the main features of 櫻坂46メッセージ is the "Talk" function, which is a monthly paid service. Subscribers can also send fan letters to the members, with different templates available depending on the type of message they want to convey. The fan letters are a paid service as well. It is worth noting that the letters can only be viewed by the members and cannot be seen by other users, ensuring privacy and security.

In addition to the "Talk" function, the app also allows users to check the official blog of 櫻坂46, ensuring that they don't miss any updates. Users can also receive notifications for blog and news updates, which can be easily set up in the app's settings.

Overall, 櫻坂46メッセージ is a lifestyle app designed for fans of 櫻坂46, providing exclusive content and a convenient way to stay connected with their favorite members.