1. Kindle. If you want access to your ebooks across various devices, you can't beat the Kindle app. If you own a Kindle or not, you can still read the books on the Mac, the PC, the iPad, iPhone, iPod, on the web, or on an Android device. Your books are synced everywhere and you never are without a book. Great for uploading your own PDFs and documents for study as well.
2. Reeder. That's no misspelling. That's the name of my favorite mobile RSS reader. All of your subscribed blogs or google reader subscriptions are synced. From this app you can read, share, and browse all your RSS feeds for keeping abreast of the best apologetics blogs, for example. You can also send articles to other services for later reading if desired. There's also a desktop app for Mac and a great version for the iPad, both top notch RSS readers. I'd say the best.
3. Pocket. This app was formerly called "read it later," which is exactly what it allows you to do if you don't have time to read a particular blog post. If you find something interested online or in your RSS feeds, just send it to Pocket. Then you can read it later in a more attractive and easy-on-the eyes format. Again, this keeps in sync with your online Pocket account and you can keep all your reading material in sync.
4. Lisgo. This app is gold because it saves me so much time. Why? Because I don't always have time to "read it later." However, the Lisgo app syncs with your Pocket account and will read your blog posts to you aloud. The text-to-speech engine is pretty good and allows you to listen to blog posts while doing other things, like driving, doing chores, etc. The interface leaves much to be desired, frankly. But the concept and the function are extremely useful and straightforward.
5. iCatcher! I think I've been through every podcasting app out there, and none of them really do it right, in my opinion. However, iCatcher! is the best one I have found as far as practical functionality. It gives the user just the right amount of control over playlists, sorting, and podcast management, while balancing a relatively intuitive interface and full feature set. Of course, one important aspect is the speed function, allowing you to listen at faster rates for your chosen podcasts. This is a real time-saver.
6. Swift Player & Downloader. This app is a recent find, and an instant favorite. Do you ever find a YouTube video that you want to watch, but don't have time to watch it sitting at your computer? And even if you did sit at your computer, the lecture is at normal speed and eats up and hour of time. This app makes it possible to download, save, and play videos from YouTube, Vimeo, and other sources for later listening... at variable speeds! That means you can watch/listen to that YouTube lecture at double speed while commuting. A superb app that I had been waiting to arrive for a long time.
7. Tecarta Bible. Now that we're looking at Bible apps, we'll start with the one that's a no-frills, functional and straightforward tool. It's not distractingly pretty, like some others. And it's not got "feature-bloat", like some others. It's just a good everyday Bible app. However, the development seems slow from the company, with little movement on new features. But if you just want, for instance, a good "sturdy" app for reading the NIV and a few other versions, this might be a clean choice.
8. BibleReader by OliveTree. OliveTree have definitely got a great bunch of apps for iPhone, iPad, and Mac. They work well, look good, and have a lot of books available in their library. There are plenty of features, without overkill. Navigation and note-taking are both well-designed. This is probably my top choice when it comes to the best all-round Bible app for the iPhone/iPad/Mac. Of course, it all depends on your personal needs, but if you are evaluating Bible apps, OliveTree stuff should probably be around the top of your list.
9. Bible! by Logos. For those who own the Logos software for Mac or PC, this is a great companion app. The previous version was able to access your entire Logos library, but the interface was pretty horrible. However, the latest version is a complete re-design of the interface. Now you can get your entire library at your fingertips with ease. The interface can still be a challenge to learn, but when it comes to sheer power and quantity/quality of resources, there is probably no better tool than the Logos Bible! app for iPhone/iPad.
10. ESV Study Bible+. For sheer beauty and for one dedicated Bible (not a million versions and distractions), just go for the ESV Study Bible+ app. Why? It's the best-looking Bible app with the best interface and a minimal amount of distraction, while still giving you a superb study tool, the ESV study notes. There's also a free version that's just as good without the detailed notes. This is my choice for best individual, single Bible app.
So what apps have you found most useful? Any that are just plain indispensable as study tools? Please share your suggestions in the comments section below.