Stream 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 Player 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. BLE stands for Bluetooth Low Energy and means basically that the phone battery consumption is less than it used to be.
You can only stream your apps with Bluetooth, if you would like to do some settings of the Network Music Player itself (like set the default start-up volume*) or do USB playback you have to use your home Wi-Fi network.
Find the IP address - find it with the Fing app
When you want to do some settings of the Network Music Player itself (not your apps) or you want to do some USB playback (i.e. play some music on the attached USB) - then you access the Player's web pages. The web address is http:/player.local. If you instead want to stream your apps - use Bluetooth.
Unfortunately, so far most versions of Android OS cannot resolve http://player.local to an IP address. That is pretty annoying since you have to find and enter the actual IP-address of the Player into the browser’s address bar, every time... 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.
How to use Fing
All IP scanners works basically the same way. They scan the network and lists the IP addresses of all connected devices. In that list you will find the name PLAYER and its current IP address. Open up the Fing app and you will see that it has already identified the network you are connected to. Click on the “Scan for Devices” button. In the resulting list that pops up after a few seconds scroll down to PLAYER and note the IP address. You can also see that the hardware manufacturer is Raspberry Pi which is correct. [in the picture below the Player is connected both with Wi-Fi and cable]
Often your router will assign the Player the same IP address when you restart or turn on the Player again. Still it is quite tedious to keep track of the IP address all the time. The IP address will definitely change if the router is re-configured or restarted or replaced.
Make your own "app"
The Network Music Player is actually app less. There is no app to be downloaded - instead the Player offers a web browser interface. Which means when you start using your Android as a remote control for the Player you will use a web browser. That works fine, but there is a more convenient way to control the Player – make an app icon and place it onto the home screen. It will look and feel like an app...
This is done by adding the start page, actually its IP address, into an app icon that will be displayed as it would be an Android app. Every time you want to access the Player you just click on the app icon instead of opening the web browser.
First open the web browser and enter the IP address of the player. Click on the bookmark button (the star) at the bottom. In the new window that pops up with the title "Add the current web page" to click on the Home screen option.
In the next window that pops up click on the “Add to page” button. Confirm that the app will be added to home screen. The app icon shows up on the home screen and from now on you will have a full screen display of the Player, no more web browser control buttons in the way. It works just like if it would be an app.
Remark: Unfortunately, you have to repeat this procedure if the IP address changes. Usually the router will assign the same IP address when you restart or turn on the Player again, but sometimes not.
*The default volume level of the Network Music Player is initially set to 100% - that is appropriate for streaming since you want to adjust the volume from your apps in that case, but when you do USB playback (play tracks from the attached USB stick) be sure to lower the volume first.