Note for Android users: Android OS doesn’t officially support mDNS which is needed to resolve .local addresses. Although some distributions will have added this protocol some other Android based systems will not be able to make sense of these addresses. If your browser cannot resolve volumio.local you will have to use its IP address instead which by default is 192.168.211.1. An easy way to find that out is by using ZeroConf Browser which allows you to browse the LAN for devices that offer mDNS/Apple Bonjour services and identify their IP address.
Note for Windows users: If your browser cannot resolve volumio.local you will need to install Bonjour from Apple. Alternatively you will have to find out the IP address of your Volumio box. If you have connected a monitor to your Raspberry Pi you should see it on the screen most likely in the form of 192.168.x.y. Your browser will have to be pointed to http://192.168.x.y
Volumio also provides a captive portal when in Hotspot mode so that whatever address you will try to use in the browser the request will be redirected to your Volumio’s home page. On a PC in fact as you connect to the Hotspot your browser will directly open up to Volumio’s home page with the address http://www.msftconnecttest.com/playback.
An alternative to the above is to use their own app which, aside from providing the full interface to control the player, it is also able to automatically find your Volumio installation in your network.