I warn you now my conclusion is going to be “No” in answer to this question. Many reading this are going to protest as I know that there are 1.8B photos shared per day and many of these on mobile but I do think that UGC grew up on the fixed web and has not adpated to mobile fully yet — it’s still very immature and yet UGC on mobile is already massive with the likes of Snapchat, Instagram and Twitter. My belief it needs to become more sophisticated and then its will become even more massive.
The above diagram is my own person opinion and others may disagree with the precise positions, but my point is that to be a good Mobile UGC product it must be easy to add content on a mobile phone and additionally be easily distributable to all mobile phones and also have significant sophistication to make it an interesting product.
For these reasons Snapchat and Instagram score well on Ease of Mobile use but are low on sophistication and products like Youtube and Facebook score well on sophisticated content but are not so good (yet) on integration with mobile (simply because they have transferred from the fixed internet environment).
We make our own product Appies score well on both axes because it is both easy to add content and distribute to any phone as well as having a sophisticated content.