It was only in 2014 when SwiftKey made the jump from a paid keyboard app to a free one with in-app purchases (which were themes). Today, the company announced that all themes are now free. This could be due to Microsoft purchasing them back in February of this year (typically when apps are purchased, all in-app purchases become free), whatever the case may be, users will definitely love using all of the themes that are available for SwiftKey right now. They are free on both iOS and Android. In order to check out the themes, all you'll need to do is go into the menu on the left side of the prediction section of the app and enter the SwiftKey Hub. Just open the "Themes" panel and then tap on "SwiftKey Store", from there you'll find all of the themes and be able to download all of the ones you'd want.
SwiftKey currently has over 100 different themes available to customize the color and design of your keyboard. They are also launching a new line of themes called "Vivid", which you can see in the gallery below. The new Vivid themes coincide with the redesign of the SwiftKey Hub. Those of you that love Material Design, SwiftKey has a ton of Material Design-inspired themes available as well. Right now, it's unclear if SwiftKey will be adding more themes to the app in the future or not, with them now being free instead of paid.
Over the years, SwiftKey has consistently been the most popular third-party keyboard app available on Android, and when iOS brought in support for third-party keyboards, it quickly became popular on Apple devices as well. It's popular due to how well it can predict the word you're typing and even the next word you'll type. It does this pretty fast, compared to other keyboards, like the Google Keyboard, which makes typing much faster. Recently, SwiftKey went to a neural network to power predictions which has made it much faster and even more accurate. Of course that's not all SwiftKey has to offer. Another popular feature is the emoji prediction. So if you type in 'cool', you'll see the emoji with sunglasses pop up. Much easier than going in and hunting down the emoji you want to use in your message.
If you haven't downloaded SwiftKey already, you can pick it up at the link below. Remember it is now completely free.