@aab yep... not easy to find... generally I go to alternativeto.net to find what I am looking for. I did a small research. You'll find one called easyMP3Gain but not even sure if that would suit your friend... And oh my gosh the interface is ugly 😱.
I hope you'll find something.
🤞🤗😊😘
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.