i use new creator app for my new project.

specificity is:

in email conversations with clients i agree with price for selling services

all prices calculates via simple calculator in this creator's app

some clients buy few times different services (right now i just duplicate entries it is not so good)

right now is two gates - 1 gate creator's app with client's entires 2 gate email system with clients conversation

i need duplicate prices and conversations from app to email and vice versa (it is not good too)

business task is "one work application":

for all clients in database entry take all email conversations with this client

using app calculate price automaticaly

i need one business app - 

- that holds all clients entries

- for each client hold email conversations with him (with email send/receive inside)

- with internal programmed price calculator (that i can make in creator)

how to make this with creator?

or may be use zoho crm with optional (how?) programmed calculator