tsudo says: In recent years my iPhone and iPad have become my primary Bible. I use it in services, for devotions, and much more. I've used a great many Bible Apps and these are the ones that have stood the test of time
Bible The YouVersion Bible is astounding. They offer excellent reading plans, bookmarking, notes, groups, and live events. It's easy to share a verse and the plans help keep you involved daily in God's Word. The offer more translations than anyone else and most offer audio versions as well. This is my Bible App.
Bible! Logos does an excellent job of popup cross reference verses and word searches. They offer a good free library and if you are a Logos user already this is a no brainer. I still prefer YouVersion for Bible reading but Logos is an excellent app.
PocketSword Bible Study This app is a must have for deeper Bible Study. It's the only app I've found that offers Matthew Henry Commenary (concise & complete), Scofield, & Wesley Notes for free. The app could use some polish but once you get the books downloaded you'll be glad you have it loaded.
Fighter Verses - memorize bible verses / scripture memory This Bible App revolutionized how I memorize scripture. You learn one passage a week and it offers great tools like fill in the blank and verse wallpapers. Set reminders for daily or weekly. FV also offers one of the best topical indexes of scripture I've found in an app. It's a real treasure and an indispensable tool.