Moon Atlas 4+

For 6 bucks, this is worth the download to have it ready to go on your Macbook. The mapping is pretty generic but does the job of helping you find features and it's not hard to figure out. The libration and mirroring are the real reason go get this as those are what really make this a useful observing tool (as opposed to just using a web site).

It's detailed…
It's easy to operate…
It's very well done :-)

I have nearly every Lunar atlas available, from Antonín Rükl's detailed (and difficult to obtain) classic to a variety of photographic atlases, like the "Hatfield Photographic Lunar Atlas" and "Atlas of the Lunar Terminator," to a variety of folding maps. Rükl's masterpiece is actually too detailed and often difficult to correlate with the reversed view most common telescopes give. The various photographic atlases vary considerably in visual detail. Most of these favor an inverted, not reversed, view, which make them very difficult to use. This app gives you the best of everything: compelling visual detail, the ability to display the current terminator, and the ability to adjust the view, flipping it up and down, left or right. Well worth the modest price. The iPad version is a perfect companion, as you can bring it out with you to view. In fact, I found this app such a visual pleasure that I got the Mars Atlas.