There are two Cloud Signage apps on Google Play. What is the difference between them?

Cloud Signage for Google Drive™ PRO is the current version of the app and Cloud Signage for Google Drive™ is the old version of the app.

The PRO version's characteristics are:

• New features were (and will be) added depending on users' requirements: including cooperative display with multiple screens, auto start on device boot, and watermark logo customization/removal.
• Per-device license system is employed: for single-screen digital signage, a permanent license is the cheapest.

The old version is not recommended because no updates are planned (except serious bug fix). Also, newer Android versions (Android 12+) will not be supported.