Digital receptionist to block nuisance calls?

[Jonathandentron]

I block pre-recorded nuisance calls on my landline with a PC-based digital receptionist requiring callers to press a key before the phone even rings. This is 100% effective.

Is there an app available which will do the same thing on an Android phone, does anyone know, please? I know you can subscribe to cloud receptionist services, but that's really overkill for this situation.