The new fMSX-Android 3.9.1 release is ready for you to download from the Google Play:

https://play.google.com/store/apps/details?id=com.fms.fmsx.deluxe (full version)
https://play.google.com/store/apps/details?id=com.fms.fmsx (free version)

This time, I have added the function to automatically download the pictures of software boxes and show them in the File Selector, wherever screenshots are not available. You can enable this function with the "Download Box Art" menu option. The DropBox support has also been improved: it no longer requires you to enter the password every time, and your game progress gets uploaded to the DropBox when you finish playing. The BACKSPACE key on the virtual keyboard has been fixed, and both Gallery and DropBox will work with Kitkat SD cards in this new fMSX version. See below for complete details.

• Fixed "BACK" button on the virtual keyboard.
  
• Now automatically downloading box art images when on WiFi.
  
• DropBox no longer requires login every time you open it.
  
• Gameplay saved back to DropBox after you are done playing.
  
• Enable "Download Box Art" in File Selector main menu to download box art.
  
• Choose "Download Box Art" in context menu to find box art for one game only.
  
• Added Gallery support for SD card folders on Android Kitkat.
  
• Added DropBox upload from SD card folders on Android Kitkat.
  
• Hopefully fixed "O" button on Sony Xperia gamepads.
  
• Improved decorative background in the portrait mode.
  
• Upgraded DropBox SDK to the latest version.