The process can work well, and it can save you considerable time while still having a nice, polished app on multiple platforms. There are a few pitfalls with the approach, though. One of the main troubles is developing for iOS first.
One thing to watch out for would be:
-webkit-linear-gradient… versus -webkit-gradient…
I’m sure that there are several other major differences between what is supported between Android and iOS. Once I find more, I’ll let you know.