Unioncy on the other hand is all about your products and your ownership experience. In practical terms, one big difference is our data. We have gathered information around your products like user manuals and warranty details and provide this information for you instead of you having to enter/upload it manually. It follows, that we think that our user is different from Itembase and Slice. There are more differences and many directions that this can go so definitely room for more than one player in our view.
Regarding Gmail, I've already mentioned several times in this thread that this is our first solution and more ways of adding products will come. Thanks!