We are happy to announce that we are now carrying the GBxCart RW v1.3 Pink by InsideGadgets! An open source (CC BY-NC-SA) device suitable for GB, GBC and GBA carts so you can backup your game ROMs, backup/restore save games and write ROMs to supported Flash carts.
View their complete product page for more information or to buy from them directly.
https://shop.insidegadgets.com/product/gbxcart-rw/