Welcome to Logeion for the iPhone! Type in the first few characters in the search box at the top of the screen and you can enjoy the freedom of all those dictionaries and reference works on your iPhone:

Here you see the side bar (reachable by a tap at top left, or by swiping in from the left). It features information about word frequency and collocations. At the bottom you see that two of the textbooks have libertas in their vocabulary.

Tap the little info button at the bottom left to go to our in-app instructions and legal fine print. Tap ‘Report a Problem’ to… report a problem.

What if you want to look up an equally liberating Greek word? No need to bother with diacritics of any kind; however, you should use your iPhone’s built-in Greek keyboard to type the Greek letters. Tap on the full word, ἐλευθερία, in the word list when it appears to see the entry. See the images at the very bottom of this page if you need to install a Greek keyboard.

Here it is. Immediately to the left of the headword you see the three grey bars you can tap to get back to the side bar, which will now show you the frequency, collocations, and textbook chapters associated with the words.

Here is the side bar view for ἐλευθερία. Clearly, Greek authors are particularly interested in freedom for Greeks. Note that the subtle line beneath ‘H & Q’ in the bottom left means that you are seeing the entry corresponding to Hansen and Quinn's’s
Greek. An Intensive Course. To see the entries for other textbooks, tap on their abbreviated titles.

Below are two shots to show you how to install a Greek keyboard on your iPhone; it works the same way on an iPad. Go to your Settings, select 'General', followed by 'Keyboard' and 'Add New Keyboard, and finally, find the Greek keyboard. With a bluetooth external keyboard, you can even type polytonic Greek.