A new Retro Replay tool by FMan 

Make your own Retro Replay ROM with FMGPUCCRBR (aka Custom ROM Builder) by FMan!
This Amiga / PC utility creates a flash-ready ROM image with a bootmenu from
programs of your choosing.
It is available from CSDb. Have fun!

AmigaOS 4.0 compile by Spot / Up Rough, this software is untested as I don't
have a Retro Replay Cartridge. So please report how it works for you.