Speaker Booster Amp Metal Bass is a free iPhone app developed by Van Hieu Tran. This app is designed to help you increase the volume of your Bluetooth speakers, allowing you to enjoy your music on high volume levels.

With Speaker Booster Amp Metal Bass, you can easily control the standard volume and boost it as needed. The app offers high definition Bass Boosting and EQ Amplification, creating an enhanced music experience. It even includes a preloaded Metal Bass preset for the equalizer.

However, it's important to note that the app comes with a disclaimer, reminding users to be careful with their hearing and devices, as the developer is not responsible for any damages.

Please be aware that the app offers a subscription service, which will be charged to your iTunes Account upon confirmation of purchase. The subscription will automatically renew unless you turn off the auto-renewal feature at least 24 hours before the current period ends. The cost of the subscription depends on the selected plan.