I think the idea of an app that enables you to choose a particular chart is great, and the credentials of the people involved cannot be doubted. Charts seem to be well executed.One small critique, and I have this same one for most astronomy apps, the red filter should be right on the main screen like SkySafari does. Not buried in a menu. Give me a button to choose right when the app opens. It's just something that bugs me.

In map 13, in the constellation Coma Berenices, M53 is labelled M35. You might want to update that. I’m pretty sure it’s an error.

I think for basic star charts, which is what these are, no more no less, $3.99 is excessive. For star charts, I prefer Star Atlas (which unfortunately is an iPhone app and not universal) which has greater functionality and is currently free (even when it wasn't free it was only $ .99). For example, in Star Atlas, you can search by Messier Number, or Constellation Name and when you select the item, the appropriate chart will automatically be brought up on the screen with the desired item centered!

I like this app a lot, as it does exactly what I want: a quick star atlas without a lot of bells and whistles and settings. However, even the white-on-black "night" mode is too bright in the field and should be supplemented with a red-on-black mode.