CH_ASUSReplied to your questions, but yet to hear anything else from you?
Can you describe more about the Twin App "make the same account"? WhatsApp account or Google Account? Generally you'd want your Google Account the same , but whatsapp account different (using the 2nd phone number or whatever)
Not sure what you mean by one way, but Call recorder works to record both parties in a phone call.
Which version and FW of the phone do you have?