- On older Android 10 versions, gesture navigation is disabled for third-party launchers (like Niagara Launcher) in general. We can't change this, unfortunately. In this case, you have to wait until you get a firmware update.
- Gesture navigation and Android's recents screen (the screen where you see all opened apps) are controlled by a submodule of the preinstalled launcher, not by third-party launchers. This means that gesture navigation may behave differently in combination with third-party launchers than with your preinstalled launcher. However, we can't change this either.
- You can download these apps to get gesture navigation on any Android version. However, you can't get the same result as with Android 10's gesture navigation.
Android 10 introduced a new way to navigate on your phone. Instead of three buttons at the bottom, gesture navigation lets you swipe through your apps.
However, Android disabled gesture navigation for third-party launchers on the first builds on Android 10 because the developer team struggled with lots of bugs:
Custom launchers are another area where we’ve heard feedback and we’re continuing to work on issues, particularly with stability and Recents. Starting in Beta 6, we’ll switch users to 3-button navigation when they are using a custom launcher by default. We’ll address the remaining issues in a post-launch update allowing all users to switch to gestural navigation. (Source)
In December 2019, Google released a patch that allows gesture navigation to work with third-party launchers. Your phone manufacturer needs to integrate this patch into their codebase. This can take several months. Moreover, if your device runs on Android 11 or higher, gesture navigation is available for all launchers.
This message you see above is misleading. It's your system that doesn't allow the launcher to use gestures. Other launcher developers are also writing about this:
This messaging makes it seem like the 3rd party launcher does not support gesture nav, when in fact it's Q's gesture nav that currently doesn't support 3rd party launchers. [Source]
Because third-party launchers cannot interact with the first party-launcher submodule that provides the recents screen, some animations cannot be supported by third-party launchers (example). [Update 13 Jan 2021] Third party launchers can now add this animation on Android 11 Pixel devices. We're working on it :)
Does Niagara Launcher support Quick Switch?
Unfortunately, not. Niagara Launcher isn't based on Launcher3 (Google's Open Source Launcher), it would be very time-consuming to implement, and it'd only work for a tiny user base anyway.