You are reading the documentation for Angular InstantSearch v3, which is in beta. You can find the v2 documentation here.
While none of the following are natively supported with Angular InstantSearch, it’s possible to make mobile apps with Angular using Ionic.
Using Angular InstantSearch in these frameworks shouldn’t be any different than on the web.
If there’s any issues you have with this, please open an issue on the GitHub repository with a reproducible example so we can help you.