I have an existing Zoho app to track clients and tasks that I would like to add an estimate module to. I like much of the functionality in Zoho Invoice, but I would want to tweak it (e.g., ability to subtotal and roll multiple line items up), so just linking the two is not the answer. Also, once we have Estimate working, would want to add Purchase Order, which would be very similar. With success of this task, there would be considerable follow-on work, so looking to establish a relationship with a talented coder who can communicate well.