File deletion on USB OTG Mass Storage Device

Question

I have an mp3 player that is connected to the smartphone.

The class is: 0x08 (Mass Storage)
The subclass is: 0x05 (SFF-8070i)
The protocol is: 0x50 (Bulk-Transfer Only)

(see the debug log from my previous question: USB OTG File Deletion)

For some strange reason, the only working app available for Android appears OTG Disk Explorer Pro. Yet it has no function of file deletion.

Have you ever had such a problem before? Is there any apps for Android that works with connected storage devices properly?

If not, would you point out how to implement file deletion according to ATAPI For Rewritable Media (INF-8070.PDF)?

Edit:

Alright. I found a nice explanation on how to delete a file within FAT16 at the book "USB Mass Storage: Designing and Programming Devices and Embedded Hosts" on page 239.

Okay. Would you recommend some opensource project o a file manager for Android that I can massage into working with my mp3 player?