Multiple homes with independent HASS systems and the IOS app

This may be a dumb question, but how do I use the IOS app with two homes/hass instances. It would be great to provide locations to both and easily switch between the houses in the app.

Suggestions appreciated.

I used evenstream component to provide single interface for two instances.
Separate homes by tabs in single interface

Groups may be placed inside groups to reduce space

Thanks much. That looks like it will be just what I need.