Boost was my go-to with Reddit from the moment I heard of it. Right now I'm constantly switching between Sync, Connect, Liftoff and Voyager due to each app missing something another has.
For example, in Sync you can't view all communities in a specific instance.
I haven't been using Lemmy itself for long. I had never heard of it until all the recent stuff with Reddit.
It was finding out that Boost was coming to Lemmy that convinced me to jump.
I tried Sync and immediately uninstalled it. While I wait for Boost, I've been using Connect, which seems to be as close for Lemmy as what Boost was for reddit. I'm looking forward to seeing Boost for Lemmy once it comes out though.
I am still using Boost for reddit. Third party apps still work if you are or have ever been a mod. The only thing not working so far is that I can't upload images to posts.
Try Eternity (previously Infinity) too. It's similar to Connect, but much more customizable. I haven't used it before, but I'm trying it now and enjoying it!