Worst and useless Nothing in the app. No options to rate it with zero stars.
Useless No information at all
Not worth the time
Not quite comprehensive, to say the least. This "app" seems like it was copied wood-for-word from a folded paper guide you get for free at airports. However, it has some links that may be of use to you if you need to book accommodations and such.
Krabi - City Guide Mobile Application by Tourism Authority of Thailand.