Top 4th of July Sales Best 4K Projectors 7 Early Prime Day Deals Wi-Fi Range Extenders My Favorite Summer Gadgets Cheap Car Insurance Target's 4th of July Sale Best Running Earbuds, Headphones

Swiftkey keyboard app shoots to top of iTunes charts

Known for its powers of predictive typing, the app now ranks No. 1 among all free iPhone apps in Apple's App Store.

Screenshot by Lance Whitney/CNET

Swiftkey's move to the world of iOS has already scored it top spots among iPhone and iPad users.

Nestled in the top charts at Apple's App Store as of early Friday, Swiftkey is the most popular free app for iPhone users and the second most popular free app for iPad users. Already beloved by many Android users, the keyboard app debuted in the App Store on Wednesday with the launch of iOS 8.

"Obviously we're overwhelmed that SwiftKey Keyboard shot to the top of the charts after launching on iOS 8," Swiftkey Chief Marketing Officer Joe Braidwood said in a statement to blog site BetaNews. "We've worked really hard on getting something ready for launch and this is the ultimate reward."

Just how popular is Swiftkey among iOS users? The app surpassed 1 million downloads in less than 24 hours, its developers said in a blog post Thursday. So why is Swiftkey so popular? Well, here's how the app works:

Swiftkey offers predictive typing, so as you type the first few characters of a word, it displays a list of suggested words. Simply tap the correct word to insert it without having to type it in full. The more you use the app, the more it learns your writing style and and the better it can predict what you want to type. Swiftkey also offers different keyboard layouts, skin colors and emoji characters.

To set up Swiftkey under iOS 8, open the Settings tab, tap General, and tap Keyboard, and then tap Keyboards. Tap the option to Add New Keyboard. Tap SwiftKey from the list of available keyboards, and you'll now see it along with the other available keyboards. Tap the setting for Swiftkey and then enable the option to Allow Full Access.

Screenshot by Lance Whitney/CNET

There is one caveat. By enabling full access, you give SwiftKey permission to keep track of your typing history to better predict your writing style. You can still use the app without opting in to full access, but then you won't get the benefit of predictive typing.

Of course, you can get predictive typing in the new keyboard that Apple introduced in iOS 8. The new default keyboard also offers suggestions based on the characters you type. But Swiftkey offers a few tricks not found in the iOS 8 default keyboard, such as the ability to enter characters by swiping them across the keyboard.

iOS 8 users can easily try both the default keyboard and Swiftkey to see which they prefer. Both keyboards are certainly a welcome improvement over the standard keyboard available in iOS 7 and earlier versions of Apple's mobile OS.