Months ago when Google announced it would be retiring the Google Now Launcher, it also announced that it was releasing code from that launcher for manufacturers to build their own version with, allowing them to put a Google Now page in their pre-loaded launcher. As expected, this code is something third-party launchers would love to play with, and it's already been implemented by Nova Launcher and is in progress for Action Launcher.
There's just one big problem these launchers and others are running into: Google Play won't allow it.
In its current form, implementing a Google Now page in a launcher requires an API that's officially restricted to system apps. Manufacturers can make a launcher with it and pre-load it on their devices as a system app no problem. For third-party developers and non-root users, the API is still usable, but the non-system app or launcher that uses them has to be debuggable, and debuggable apps are not allowed by Google Play's standards.
So how can you use Google Now on Nova Launcher if Nova Launcher's on Google Play?
Nova Launcher couldn't integrate the Google Now page into its main app and risk getting kicked off Google Play, so it decided to offload that portion of the launcher to a companion app that users manually download and install once they've checked the oh-so-ominous "Allow installs from Unknown Sources" toggle in security settings. Nova Google Companion plugs into the main Google Play-compliant Nova Launcher and allows you to activate the Google Now page, just like TeslaUnread did for Nova's unread badges for years. And like unread badges, the Google Now page could eventually come to the main app but not while the API's restrictions and Google Play's restrictions both remain in place.
Lawnchair is basically a Pixel Launcher with customizable bells and whistles, and as such it has the Google Now page to the left. Lawnchair is also not on Google Play, instead existing on the developer's site as well as forums like XDA.
Is Google Now worth it?
Swiping left for Google Now while keeping all the bells, whistles, and icon packs of a third-party launcher is great, and I've used Google Now waaaay more since installing the Nova Google Companion than I had in years. That said, Google Now is also a teeny bit outdated. Google Assistant can read me the news, the weather, and control my home. Google Now's feed can show me where I parked (if I somehow forget), some headlines, and some recipes, but it just… doesn't feel as helpful anymore. I know, it's heresy, forgive my sinner's tongue, but the Google Now pane just isn't as vital to me as it felt years ago.
Some users still swear by the Google Now pane, and they are swearing to use the Google Now Launcher until the damn thing just won't execute anymore. I'm all for having the option of Google Now on my quite customized launcher, but I do wonder how much benefit it brings in an Android world where a bigger, better Google Assistant is a long-press away.