We have a business consisting of 2 contractors who are on service calls during the day. They will have tablets and cell phones for accessing Zoho. We have one mobile phone# as our main (and only) business phone. I would like all missed calls to be logged in Zoho CRM. 

What are my options for accomplishing this? I was looking at Telephony providers but we're not brick and mortar. Is there an app for the contractors personal mobile phones that will handle incoming and outgoing calls using my business phone#? Can voicemails be recorded?