Hello home smartapp deleted

Believe me, the Classic app is easy, but you are just opening up a source of extra pain when starting to use something what will go away in the future (sooner or later).

Have a look on this thread and you will understand.

ST support more thing in a better way in the new app, then in the Classic app. Out of the box. If you want to fiddle around for hours and hours with old DHs and things what might have not been changed for years and may or may not work, then of course, who am I to tell you.
ST offers now a lot of integrations with plenty manufacturers where you just need to pair the device without thinking of the background of it. It is almost plug and play. It makes things easier for everyone.