It takes care of querying, managing search state and updating your UI. There are 10 built-in components: https://docs.appbase.io/docs/reactivesearch/vue/overview/Sho... which can help one get started in minutes. However, it's very much designed to allow bringing in your own UI components and design systems.
Thanks for the compliment. :-) The UI components would always remain open-source.
We offer a hosted search service at appbase.io which funds this and have very recently started offering it more broadly as a managed platform for any ElasticSearch upstream. It offers a better search development experience, out-of-the-box search/click analytics and more fine-grained security features: https://medium.appbase.io/appbase-io-clusters-a-supercharged....
When I got to the downloadable Sketch components, I started wondering if the website was mining cryptocurrencies or something. It seemed too good to be true.