On my android phone when receiving a call I have two standard options, reject or accept.

I would like to have 3 options. Reject, reject but send to voicemail or answer. I can see no end of apps in the store but can't really see the wood for the trees. I'm not particularly fussy about black lists and white lists etc.

Can anyone recommend?

you know when you reject a phone call it sends it to voicemail automatically right?

mu understanding would be that if a rejected call is sent to voicemail or not is a network level feature.

the usual 3rd option is to silence the ringer so they person calling can't tell that you have rejected the call.

Yes, but what if you want to reject the call outright because you know the caller is just going to leave an irrelevant voice mail message?

Answer and hang up immediately after

This is pretty much what the Black list concept was invented for.

Yeah thats what i didn't understand. I wonder if the OP realises what blacklist means?