I am still looking for some helpful Greek apps for my android phone. Most bibles I have don’t display Greek fonts properly, or I don’t know how to get them to do so. The best bible that does do so is Cardre Bible. It’s brilliant and you can download versions for when there is no connectivity. I have some great Greek vocab learning apps too. The best are “Bible Flash cards” and “Bible Greek Flash Cards”. They both include vocabulary for Mounce’s basics of biblical Greek.
What I would really love though is an easily searchable, offline Analytical Lexicon App. So far I have not worked out how to use/search the Logos ones easily. Here is quite a good internet NT greek lexicon tool though.