At the moment this is very much a work in progress at it's very earliest existence. At the moment all it has is an entry in the Blizzard AddOn options page and a minimap button (with options to hide the button and lock the position). It does have a frame that can be toggled open and closed but doesn't actually do anything meaningful yet. By all means follow this and keep an eye on it if you think it will solve a problem for you.
It has appeared on here because I was getting the workflow to automatically upload it here when I released something and was a test.
At the moment I am just aiming this at the Retail version but don't see a reason once I've got it to a decent place that it wouldn't work with Classic with hopefully minor fixes. After all, I'm fairly sure I'm not doing anything particularly ground breaking.
I decided to make this when I was running low level instances and kept on getting a lot of low level stuff I didn't want to keep and wanted an easy way of selling it.
I did find the Instance Loot Manager by LukasasPlays but found it didn't work very well with my Bag addon (BetterBags) because of the core functionality of how it tracks the things you have picked up. Definitely check his out if you think it will serve your needs.
So after a long time of thinking about making an AddOn , I finally decided to have a go at making one myself.
Some features I plan to include:
I plan for it to only sell what you picked up, E.g. If you have 10 Wool Cloth in your bags when you started and then pick up 5 the AddOn will only sell 5
Filters to keep certain quality of items
A way of keeping an item if you don't currently have it in your collection
Option to keep trade skill items/reagents