Android - consider streaming with Bluetooth

The most convenient way to stream your apps with Android devices is to use Bluetooth. When you stream you control every aspect of listening with the app, like setting the volume, play/pause, next and so on. The Network Music Streamer supports Bluetooth 5.0 and that version is supported by most modern phones. With this version comes a wider range and increased transfer capacity which improves sound quality up to be like CDs. Bluetooth is backwards compatible, so you can use older devices, but they might not always be able to benefit of these latest features. 

... or stream your Spotify app (when the streamer isconnected to Wi-Fi), the streamer is integrated with the Spotify app so you can choose Player as the Spotify device within the Spotify app. That requires a paid premium account. 

If you only have the free basic Spotify account - stream Bluetooth! 

Find the IP address - find it with the Fing app

When you want to do some settings of the Network Music Streamer itself (not your apps) or you want to do some USB playback  - then you access the streamer's web pages. The web address for the start page is http:/player.local

The format of an IP address for private networks most often looks like this: 192.168.n.nnn. To find the IP address you need to do a network scan. That is not as complicated as its sounds. There are quite a large selection of network scanner apps available on Google Play. Retro Audiophile Designs recommends Fing as the way to find the IP address, since it is easy to use, well-proven and the basic version is free. It can be downloaded from here

Note: iOS, macOS and Window devices are able to find local URLs on private networks (i.e. your home network) - so if any of those are around you can easily find the IP address on the start page http://player.local .