Top Shelf Calendar app for iPhone and iPad

Top Shelf Calendar aims to be a TV equivalent of the classic wall calendar:
Beautiful pictures combined with your dates and events of the day.

As tvOS currently does not support the EventKit api, this iOS companion lets you export calendars from your phone or tablet to iCloud. Once in iCloud, you can access it through the app on your TV, so you dont have to enter all your dates and events manually.

Top Shelf Calendar is meant for a family/shared environment:
Show events everybody should remember (grandmas birthday) or meetings that will probably run long (so dinner time will have to planned accordingly). The TV presents the perfect opportunity to communicate it to everyone.
As you might not want to share all you calendars, the Calendar Export section lets you select which ones to export.
Imported calendar events on Apple TV will be tinted yellow to distinguish them from ones entered on device. iCloud-based events will be available as read-only as changes would not synch back to iOS. Local deletion is still possible, though (long press gesture).
To speed up this process, starting with the 1.3 update, there is now a widget to export the current calendars without starting the app.

This iOS app also provides a way to enter a reminder, which will then be sent and displayed on your Apple TV. This, again, is done via iCloud, so make sure to be logged in with the same ID.

Users can now choose up to 12 custom images from their photo library with the companion app.
The Apple TV app presents the "Custom" option as part of the theme selection.
It will only be enabled, once photos were selected on iOS.