A free app for Android, by Ronasoft Media.
Volume Booster is a simple and useful app to amplify your audio. It’s a tiny dynamo that unleashes a symphony of sound from your device or headphones, which is great for people who need louder audio from their device or headphones.
With Volume Booster, you hold the reins of sound power in your hands. This trusty companion is perfect for those who crave an extra boost to their audio volume. Volume Booster app supports speakerphones, headphones, loudspeakers, and external speakers.
Caution is key when using this, however. Playing audio at high volumes for an extended period can wreck your speakers and even damage your hearing.