Wordpress Custom Calculator Plugin

General information for the website: Accountant
Description of every page/module: Looking for a stand-alone script/ plugin for calculators to be integrated into accountant websites.
Must be customizable. Propose more user engagement and lead generation features to win.

Must work like this and layout also be similar to this site - https://www.accountsandlegal.co.uk/philosophy/calculators
Result should come out like this site : https://www.parkercavendish.co.uk/resources/online-calculators
No Formula Will be Provided. have to calculate from the examples.


Calculators:
============
Income tax Calculator
Capital Gains Tax
Maternity Calculator
Redundancy Calculator
Inheritance Tax Calculator
VAT
VAT Flat Rate Scheme
Self Employed and Freelance Tax Calculator
Freelancer and Sole Trader Take Home Pay Calculator
Company car and fuel benefit-in-kind
Fuel costs calculator
Gross profit calculator
Loan calculator
Mortgage calculator
Millionaire calculator
Payslip calculator
Startup calculator
CIS tax deduction calculator

Quiz :
Limited vs Self Employed
VAT registration Quiz





Examples and Calculations:
http://www.jonesandpartners.co.uk/calculators
http://www.hadleysco.com/resources/business_centre/business_calculators/index.php
http://www.hadleysco.com/resources/tax_centre/tax_calculators/index.php
http://www.easyaccountancy.co.uk/calculators-0
https://www.parkercavendish.co.uk/resources/online-calculators
https://www.parkercavendish.co.uk/resources/online-calculators
https://www.accountsandlegal.co.uk/philosophy/calculators

Proposal
========

You should be very specific and must be able to fulfil all the requirements.
Must not be over budget
Submit detailed Proposal
Establish your understanding of the project by demonstrating what and how you going to achieve these.
Clear pricing and ETA
Must clarify how long you going to provide free support and How much for paid support
Description of requirements/features: Requirements
============
1. Stand Alone wordpress plugin
2. Settings Must allow to change percentage or other variable if needed in future.
3. settings Must allow to change colour and layout to match whole website
4. Must Use latest technology (e.g.: angular 2 instead of annual 1)
5. Payment wont be released until work is satisfactorily completed
6. You must figure out all calculation algorithm from bellow example.
7. We should have sole rights on this project.
8. surrender source code and sign NDA
9. Must Provide documentations
10. Name and Email should be submitted to database before showing result.
Specific technologies required: wordpress, php, javascript, css
Similar urls: https://www.accountsandlegal.co.uk/philosophy/calculators
Extra notes: