inventory software

I think Scalemates has a stash inventory feature if you create an account.

I use Microsoft OneNote to inventory kits and Excel to inventory paint.

Once upon a time, an IPMS club in Alabama did an Access database to inventory your stash. It was very data entry intense. It might still be out there in the interwebs.

Right now, I've been using Scalemates' database stash thing, but I don't add stuff regularly, only when I think about it.

I also use Excel for both paint and kit inventories. Once set up with headers and convenient column widths, etc., its easy to work in. 

I imagine that if you search the open source database community you might find something that will work with the Barcodes on items. Scan the Barcode and maybe add a picture to a database. 

Another vote for Excel.  I use it to keep track of my model, game, and book collections.

For models I use columns for Category, Manufacturer, Kit name, Kit number, Scale, location (where it is stored).  Very easy to use.

And SWMBO will not let me take new acquistions up to the hobby room until it has been added to the spreadsheet, so it is always up to date.  I send the list to my email/phone so that when I am at a flea market, model show, hobby shop, etc., I know what I have and can decide if I need or want a double or it's a kit I need.

I use Scalemates to keep track of my stash. I don’t quite have all of my AM stuff in there, but my kit inventory is up to date.