I'll be honest, this has been mostly a solo project over the years. My good friend Yulia, from Ukraine, helped me immensely with learning Russian, which was the language she used. Since the war, like most Ukrainians, she now only speaks Ukrainian. Alejandro, my kindred spirit, helped me with some Spanish, but we didn't really sink our teeth into it, and he is now busy with his own business. I had many people help me learn Indonesian years ago, and that's where the whole concept of a better way to learn languages originated.
The method can be applied to all languages, equally well, but it also needs to be tailored slightly for maximum efficiency with each language. You can learn more information on the method here. For more information on me, you can ask if you're really curious.