Theme engines are becoming a rather popular feature for this year's devices, as we've seen the likes of HTC's upcoming theme engine debuting on the HTC One M9, which is their flagship device for 2015. Sony has been implementing a theme engine on their devices for quite some time now, and rooted users running on CyanogenMod or any ROM based on CyanogenMod have had access to a theme engine for years. With the arrival of the Galaxy S6 and the Galaxy S6 Edge, Samsung fans will officially be getting access to a stock theme engine that is built into the device, the sad thing is that it will likely not be available to older Samsung Galaxy device owners initially, although perhaps Samsung will see fit to push it out to older devices in an update.
The good news is, for rooted users at least, that enterprising developers over at XDA have unofficially ported the themes from the Galaxy S6 for use with rooted users on the Galaxy S5, the Galaxy S4, and the Galaxy Note 4. According to the thread at XDA, those are currently the three devices the themes have been tested on and have worked, so if you own one of those three devices and you happen to be rooted, you're able to give this a shot. It's worth noting however that the themes only skin the launcher and do not theme the entire system as they do on the Galaxy S6 and the Galaxy S6 Edge, so things are still a little limiting, the device also needs to be running Lollipop for these to work.
Lollipop Theme Enabler gives older device users a way to get a little bit of customization before hopping over to a new device, something that might help those looking to upgrade decide whether or not they like the look of themes prior to a purchase of the handset once they launch. For those who are also perfectly content with the device they have but simply wanted to theme their launcher to look like the themes offered on both Samsung's new flagship devices, this seems to be the solution. Once the Galaxy S6 and the Galaxy S6 Edge are released, it wouldn't be surprising to see a full port of the theme engine from the Galaxy S6 made available for older rooted Galaxy devices.