An update has occured. With the following new features.

• Frameskip implemented – Boob!boy should now be faster with
  only a small amount of frameskipping noticeable. For example, Super Mario
  Land without doubt now runs at FULL SPEED.
• Super Gameboy Support added. You can now play games such
  as Pokemon Red, if you really want to.
• Fixed a memory problem that meant memory wasn’t being freed
  up after the game was exited and hence when you had played 4/5 games the dc
  would run out of memory and crash. You should now be able to play as many
  different games as you want without having to reset the dc!
• Swapped around A and B keys to make it more like a real
  gameboy!
• New menus – a license screen is now displayed explaining
  that Boob!boy is not licensed or endorsed by Sega. Also a menu screen has
  been implemented which currently only features a "Play game" option…
  (pretty pointless at the moment then – just press start to skip past this
  menu!)
• Made game-select screen more user-friendly by speeding up
  page-select and game-select movements
• Fixed bug causing a delay before loading the game to be
  played
• Implemented load-from-file functions, saving much-needed
  memory… this also has resulted in a speed-up in the emulation since Video
  Ram can now be used for more important tasks!
• Found and "zapped" other little bugs in the code,
  which although didn’t cause any problems in current versions would have done
  so in the future.

On a side note the author stated this may be the last release.
You can pick it up on the boob page shortly.