I use Kvaesitso, it is one of the better open source launchers with a lot of customisability and a very clean design.

I’m using Niagara personally, but I know it’s a radically different experience and probably not something I’d recommend to anyone looking for something comparable to Nova. Niagara is also not FOSS if that is a priority.

I know there are some FOSS launchers out there with similar features to Nova that folks on Lemmy have recommended in the past, but I don’t know them offhand and haven’t used them myself enough to be a judge of quality.

It’s probably not even bad sticking with Nova, because at least to my knowledge they haven’t gone sketchy yet, but it’s something to keep an eye on. Analytics companies typically aren’t very trustworthy, especially when it comes to user privacy.