The Galaxy S8 has a bigger focus on audio than any previous Samsung flagships. The speaker gets surprisingly loud, nice AKG earphones come in the box, and the onboard Bluetooth 5.0 enables features such as Dual Audio (the ability to stream to two Bluetooth devices simultaneously). In keeping with this theme, Samsung has just published a SoundAssistant app on the Play Store for Samsung devices running Android 7.0 Nougat+. It's pretty cool.
left: All the options. middle, right: Scenarios.
The first option you'll see is 'Scenarios.' If I remember correctly, LG has a very similar thing built into their UI. Essentially, Scenarios allows you to customize your phone's sound depending on what time range you select. By default, you'll see 'Home,' 'Work,' and 'Sleep.' You can tweak the name, the days, the exact time range, and what you'd like it to do at that time. For example, you could have your phone automatically switch to vibrate mode and disable media volume when you get to work. Depending on your daily schedule, this could be very handy.
Note the tiny floating button in the second picture.
Moving down the list, 'Floating Button' is the next feature. Basically, this allows you to fine-tune your sound without having to open the app every time. If you enable this, a small floating button will appear on the left side of your screen (you can rearrange it). Press it, and you'll be able to tweak your volume intricately in a range from 0 to 150. If you have an app currently playing sound, you can adjust that as well. There are two buttons that appear on the top right of the prompt; the left one opens a popup of the 'Sound Quality and Effects' section in settings, and the right one opens SoundAssistant. For such a tiny button, you can do a lot with it.
The next option is 'Control media volume,' which allows you to choose if you'd like your volume rocker to adjust your ringtone volume or media volume by default. I'm seeing a lot of people hyped to see this, but after checking several Galaxy S8s, I realized that this feature came stock (Settings -> Sounds and Vibration -> Default Volume key control). However, this wasn't the case with previous Galaxy devices, so this may still be a good reason to download SoundAssistant.
'Individual app volumes' is pretty self-explanatory; if you'd previously tuned the volume for a specific app, you can either adjust it here, or remove the custom setting altogether. This option is probably best if you have a game or music app that you want to hear the sound from, but the default is too loud. Under 'Control Audio,' 'Dual app sound' allows you to play audio from two apps at the same time, and 'Always play using phone' lets you choose specific apps to only play through the phone's speaker. It seems that both of these features are dependent on what device you have.
The last two options are also easy to decipher. 'Mono audio' will switch the sound from stereo to mono (in both earphones), which means that if you're only using one earphone, you'll still be able to hear everything. And 'Left and right sound balance' lets you choose what percentage of the sound goes to which ear.
All in all, this app packs a lot of functionality into a small 4MB package. It's available in the Play Store, but should you live in an unsupported country, we've got the APK over at APK Mirror. Samsung says that this will only work on 7.0+ Galaxy devices, but you're certainly welcome to try it on other devices.