If you use the Adobe Creative Cloud, you could simply make a CC Library (or libraries) of assets to share. You can add notes to assets, organize things into subfolders, search across multiple libraries, etc. Everything syncs via the cloud, so you can update assets on the fly to deploy to everyone on your team. It's not amazing, but it does the job for the most part.
The Noun Project has also has a simple DAM app called Lingo which might be worth checking out, though I don't personally have any experience with it.