I have one of these.
http://www.banjobrothers.com/product...handlebar-bag/

It has a clear map pouch that is velcroed to the lid of the bag. I have used the map pouch to put my phone in while touring. The map pouch does not seal closed, so its waterproofness is limited to keeping water from getting into the open end. Though I have ridden through some all day downpours and water did not seem to get in the map pouch. The bag itself is completely waterproof from my experience.