4 stars: Samsung Galaxy S8 folks, THIS APP WORKS. No joke, here's how.. First, be sure to already have music playing from any app. Next, open THIS app and go to EQ to be sure toggle is ON. Lastly, under 'BOOST' tab, slide 'Loudness Booster/Amplifier' all the way to zero, then VERY SMOOTHLY touch and slide this fader all the way to the maximum. This REAL BOOST works well as long as sound remains playing. If you stop playing music, you may need to 'RESET' by repeating last step.
5 stars: App does what I needed it to do. My phone raises and lowers the volume in large increments. Push the volume buttons and you can see how much the volume-level indicator moves. You could also hear a dramatic difference in each push if the volume buttons. This app shows the percentage level of my phone's volume. The last increment before silence on my phone, using my volume keys, is 24%! The phone goes from 24% volume to 0% in one push of the button! This app allows me to change the volume on my phone in 1% increments. Exactly what I wanted. Perfect for my needs. Another nice feature is that you can have presets for situations that require different volume levels. I have one for sleep. I turn on the sleep preset and the call, audio and alarm volumes all go to a level I set.
3 stars: Works okay, probably need to learn more about how it works. Every time I want to adjust the master volume down, it automatically changes my phone's media volume UP, which I then have to re-adjust back down....