Fleksy claims to have "probably the most powerful text prediction engine," which might be true but distracts from the fact that it's very similar in operation to a run-of-the-mill iOS or Android autocorrect engine.
The difference is less about capability, I imagine, than settings: if Apple or Google were to make its autocorrect systems more assertive — that is, have it guess at a lower threshold of certainty — it would look a lot like this. And, as with Fleksy, you would get enough misses that you'd probably want to switch back to something less agressive. Still, though, pretty cool stuff. And free to try.