Zoho Books Customization & Wave Accounting Customization

Zoho Books / Invoices Problem Statement 1: The invoice value (excl. taxes) is calculated in three ways: a) Fixed fee for project (eg. INR 5000) b) Percentage of Project Cost. (eg. if Project Cost is INR 100000, my percentage fee is 10%, I will be paid 10000 INR) c) Rate per sq. ft. (Eg, rate per sq ft is INR 25, and project size is 1000 sq. Ft, I will be paid INR 25000) These three need to be three options to calculate the subtotal in an invoice on Zoho books. The items marked in bold would be inputs from user. ————————————— Problem Statement 2: Invoices in the real world are usually created milestone wise. Eg. If total invoice value is INR 100 Milestone 1 - advance - 50% - INR 50 Milestone 2 completion - 20% - INR 20 Milestone 3 completion - 20% - INR 20 Milestone 4 handover - 10% - INR 10 1. The sum of milestone payments should be equal to the Total invoice value 2. The user should be able to create these milestones in estimates but generate invoice for specific milestones (i.e if I button is in front of each milestone that says “create invoice” - an invoice should be created for only that milestone) ————————————————— Problem Statement 3: The above two needs to be replicated in the form of a plugin / customisation for Wave Accounting as well.