Problem Description

I'm looking to create a plugin for change tracking ("redlining") for excel workbooks, very similar to how redline change tracking functions for word docs. The basic functionality of this plugin would enable a user to compare an initial version of an excel workbook (version 1) that has had no changes made to it, with a modified version of the same excel workbook that HAS had changes made to it (version 2).

Acceptance Criteria

Basic functionality would look like follows:

1. I am in excel workbook (saved as version 2) which has some changes made to it
2. I would like to compare the changes that have been made from the base version (saved as version 1)
3. I click the plugin icon, then select which excel workbook I'd like to make the comparison with. I click version 1
4. The plugin then automatically outlines in red boxes cells that the user has changed since version 1. Boxes outlined in red should ONLY include changes where a user has manually changed the formula or input number in the cell
5. Should be able to hover over a redlined cell to reveal the prior formula or input, with option to insert previous formula or input value
6. Ability to save a redline version that displays red outlines

Please outline how you intend to approach this plugin / steps to complete.

Key Points

This is not a web app, it is an excel plugin.
This is not a tool for Google Sheets, it is for Excel only.

Tool with similar functionality (but for PowerPoint) that functions similarly

Link to website: https://www.flippr.ai/
Link to demo: https://www.youtube.com/watch?v=LInebE2s3ug