Adobe Express replaces Adobe Spark on the web and Adobe Spark Post on mobile. It does not replace Spark Video or Spark Page, which will remain separate mobile applications with all the great features and functionality that you know and love. You can download all of these apps via the Apple App Store.
As a Spark Video or Spark Page user, you can still access all your projects on the web via Adobe Express. And you can create new projects with Spark Page or Spark Video on mobile and continue working on them on the web via Adobe Express and vice versa.
If you want to upgrade, subscribe to the Adobe Express Premium plan, which includes all the premium features on both mobile and web for Spark Video, Spark Page, and Adobe Express. You will also have access to premium features in Adobe Premiere Rush and Adobe Photoshop Express.
If you have additional questions, please visit the Adobe Help Center at helpx.adobe.com/support.