Photone allows you to view your photos & videos (everything in the Photos folders) from Microsoft OneDrive on Apple TV 4th Generation models onwards.
If you have many (I have 21,000+) photos then Photone does not wait for all the information to be downloaded before displaying any thumbnails. Instead photos become available as soon as possible. When downloading thumbnails multiple are downloaded simultaneously giving you quick access to your photos & videos.
The latest version now defaults to performing incremental updates using the latest Microsoft OneDrive Graph API. This means that initially it will download the information for the photos and then after that just the changes meaning all the photo information is available immediately.
It consists on an iOS App that is used to sign in to OneDrive and obtain an access token (that is valid for one hour) that is then saved to your iCloud account. This is required as it is not yet possible to sign in to OneDrive directly from Apple TV.
The main App is for Apple TV which using your synchronized iCloud account is able to obtain the access token which can be used to sign in to OneDrive and download your photos.
The access token is only valid for one hour (the expiration time is shown on the iOS App). After this time you will need to re-authorize via the iOS App.
You can remove the access token from either version of the App. If you sign out of iCloud the token remains valid until its expiration time but if you sign in as another user than it will be replaced.
NOTE: A Microsoft OneDrive account and Apple iCloud account are required
NOTE1: Only OneDrive Personal, not Business is supported.
NOTE2: The iOS App is only used to authenticate with OneDrive, it does not display any photos or videos.