Android Voicemail & Call-forwarding Server & Client Application

Hello, I currently operate a DID (Direct Inward Dial) telephone number voicemail and call-forwarding service. I currently use a legacy Centigram/Mitel platform and Asterisk. The legacy platform sits in a data center and the Asterisk runs on cloud VPS. I am wondering if Android can do these two functions better, as I do not have a client application that customers can download to manage their service. I am at the beginning of this project and would like to talk with Android Telephony Developers. Thank you.