What I did was:
- Install TestFlight off the Apple App Store
- Open this link on mobile: Join the Home Assistant beta - TestFlight - Apple and click the Start Testing Option
- Once the beta version of Home Assistant has been installed, quit the HA app and re-launch it.
- Before your HA server instance loads click the orange gear button and select to add a second server
- You will be able to switch between servers by swiping with 3 fingers to the left and right.
Hope this helps!