I have a team located in the US and abroad. I need them to be able to download an app on their phone and/or computer that enables them to send and receive Calls & SMS (to outside numbers). I would like this to be built on top of SignalWire. This needs to be something that I can host on my own server (ideally Digital Ocean) and that I can use my Branding. I also would like to be able to resell this to other users/companies.