The fixed footer button for smartphones is implemented in many TCD themes, but you can choose to display it with or without an icon. The button with icon can be selected from 30 different icons as shown below. You can add as many buttons as you like. We recommend no more than 5 buttons at most.
For the no-icon type, you can set and display up to two arbitrary text and links.
Rather than a button with an icon, it would be nice to set up a pinpointed link, etc. Since DROP is designed to be a music app site, we can assume that it will have a free trial, a link to contact us, etc.