Can it be programmed without the app?

Not as far as I can tell. You need the phone app to program it via Bluetooth. I suspect that the app has all of the codes and does not need connectivity once you’ve downloaded it, but the database of codes would live in the app and not in the remote hardware.
I would prefer another Harmony to the Sofabaton U2, but the Harmony still relies on an app to program it. Unfortunately, according to this
support.myharmony.com/en-us/download#harmonyRemot…
the software is no longer available, and even if you could snag it you wouldn’t be able to make a new account to use it (obviously it’s bullshit that you need an account, but c’est la vie.) Basiclly: Harmony had good hardware and bad software, the Sofabaton is the other way around.