I would like the option to write code that answers my phone or downloads call information or operates a switchboard etc. I don't have a current application but

I would like the option to write code that answers my phone or downloads call information or operates a switchboard etc. I don't have a current application but when faxes existed I might have wanted to automate things with an app of my own devising. I am not a fan of operating systems that deliberately obfuscate things that could technically be done. If I was developing my mobile customer service app then I would like to develop it in such a way that it would not mysteriously fail due to some overly complicated access keys. Or to require a 'rooted' device. I would not expect my app to be fit for the Google store though. Or any other online app store. Maybe rather than permissions it is the store and what is allowed in the store that is a problem.