There are three main aspects to Swiftkey that make typing easier.

First, you can choose various layouts including ones with split keys (very useful if you type on a larger device such as a tablet and hold it by the sides), ones with separate numeric keys, arrow keys for moving the cursor, and more.

Second is flow. With flow, you just drag your finger across the keys rather than lifting it and pressing individual letters. It is pretty amazing when it works and, if it works for you, it can speed up your typing immensely. Unfortunately, I found it was a little hit and miss. I found I spent more time verifying it guessed right and correcting wrong guesses than it saved me, so I very rarely use flow.

Third is what really works for me - word prediction. It turns out most people have a fairly limited vocabulary and use certain phrases frequently. SwiftKey learns quickly about the words you tend to use. As you type, SwiftKey tries to guess the word you are typing and presents three options at the top of the keyboard. As you type more letters, the list changes. When you see the word you want, you can tap it. If it is the centre word of the three, you can also just hit space to select it.

SwiftKey then takes it a step further and, based on its learning of the words and phrases you use, tries to predict the word you will use next. For example, if you frequently type Home late for dinner tonight, within a few times of typing that phrase, when you type Ho, you are very likely to see the words appear in the predictions and with 5 taps, you can complete the phrase.

SwiftKey has other tricks up its sleeve, such as auto-correcting typos, accessing accented letters by holding down the letter in question, voice input, ending a sentence by hitting space twice (which removes the first space, then inserts a period and a space), auto-capitalizing the first word of a sentence, and more.

SwiftKey has support for 81 languages, and you can have three active at once.

SwiftKey keeps track of how effective it has been in helping you. Right now, SwiftKey has saved me 162,465 keystrokes, completed 71,253 words, corrected 81,290 typos, flowed 972 words (remember, I rarely use this feature), and made me 30% more efficient at typing.

I mentioned that SwiftKey used to cost a couple of bucks. It is now free. They make their money by selling keyboard themes. But not to worry; it doesn't nag you to buy something while you are typing. You will occasionally receive a notification of an available theme. That's about it.

I still miss my BlackBerry physical keyboard, but SwiftKey has probably kept me from throwing my phone against the wall more than once. Highly recommended.

Bottom Line:

SwiftKey Keyboard (Freeware)
http://swiftkey.com
Available through Google Play for Android and iTunes for Apple iOS