https://wccftech.com/cortana-app-on-android-and-ios-is-being-shut-down-by-microsoft/

The Cortana mobile app for iOS and Android is officially being killed by Microsoft today, March 31st, 2021. The app was originally launched back in November 2018, and in January last year, the app was removed from the Google Play Store and Apple App Store. While it was fully functional on both platforms, Microsoft has finally confirmed that it will no longer offer support for the app.

As per the app's support page, Microsoft talks about that reminders and lists will no longer be available to the users in the app. However, they can still be accessed through Cortana on Windows. In addition to that, Cortana reminders, lists, and tasks are automatically synced to the Microsoft To-Do app available on both Android and iOS. This is what Microsoft had to say,