3 September, 2018 update allows you to freely upgrade to PRO version of Apex Launcher, by installing the app and selecting PRO under settings of the app. Do note, this does not grant you a Google Play Pro license, it just allows you to unlock PRO features if you have it installed with the aforementioned update.
Apex Launcher Pro unlocks the following features:
- Powerful drawer customizations (sort apps in drawer, folders in drawer)
- Unread count notifications (provided by the free Apex Notifier extension)
- Convenient icon gestures (swipe up and down actions)
- More gesture options (two-finger gestures)
- Additional transition effects (accordion, cross, etc.)
- Enhanced folder support (bulk add, merge folders)
- Advanced widget options (widgets in dock, overlapping widgets)
- More features on the way!
Thanks to RichardL & Dannyboi09 for pointing out that not all devices are able to receive the latest update or may require some time for the update to propagate to all devices.
Selecting PRO then Get Apex Launcher Pro takes me to the Google Play Store and the price for the pro version is $5.99