Not sure why Bootstrap bloat is a problem if it's just going to be an internal app. I'd rather go with a more familiar, and well known framework, and not have the overhead of learning yet another framework (not to mention others who would maintain or contribute to the internal app would have to pick up this new framework)

That being said, I do like the look and feel of Flakes. Also, given that graphs and charts are key to internal business apps, would be awesome if there was some easy charting integration / capability.