While reading online books, I generally have another browser open to look up those difficult words. The tabs tend to expand quite quickly after hours of reading. If the interface were dead simple, then I would find this very useful. I've been looking for ways to expand my vocabulary. Being able to access a listing of these words that I lookup would be quite interesting and may actually help me out quite a bit. Keeping it universal is a great idea. Whenever I find myself with downtime, I'm generally looking on my phone for something to read. It would be great to access this listing on the go. I'm excited to try this out!