Primarily native code and local SQLite with (hopefully) google drive and/or Dropbox to have as a backup option. I was mostly focusing on the native app since I kind of gravitate towards that side anyways. It sounds like you're farther along with the web app. Let me know if you do go for it. I'll hold off. It'll probably take me a bit to finish up the other projects as well.
Your list of features/categories was pretty extensive. I didn't think of warranties, COO, etc. I wasn't sure about where to pull the categories from so I was checking out Home Depot and Lowe's, but pretty much the same thing.
Do not hold off for me... I started this project many years ago and it is far from being done. Mostly because it has a low priority for me (the new priority is a Raspberry Pi project with my nephew ; and finishing a tone/signal generator for iOS).
I am still not happy with the categories I have, but I am only a DIY so there are plenty of things I do not know (plus I only do repairs and almost no fabrication, so that is another aspect I do not know).
What I find takes a lot of time is doing the management of all attributes (allowing the user to add/delete/rename categories, locations, vendors, manufacturers, ...).
I am not that far into the project to be honest... the db structure is there and there is one global report, one form to enter new tools and that is it. No user profile management, no management to location, categories, no editing of tools, ... all that I do directly with SQL commands.
I will have to look at MyStuff2 as it sounds like the kind of stuff I work on (I will still do my own, but that is the geek in me).