Extensive reference but a poor GUI design

Update:

After the update and still it only supports portrait mode for a $30 app!!!! Taking another star away.
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Only one orientation is supported, the single portrait orientation. Really!? Not even both portrait orientations! Come on now! For $30 they surely can do better than that!? This is one of the more expensive apps on the Apple app store and it has a really poor user interface. I expected a better.

Eriptron about Glossary of Geology