Only the cartridges
With the Everdrive cartridges you can play ROM files directly off SD Card on the original gaming consoles, including SRAM saving. If you got a Retrode2, it's the perfectly legal way to keep your classical game collection alive and also play games where the backup-battery is long dead.
PLEASE NOTE: As PayPal thinks Everdrives are against their policies, PayPal payment is currently not available when ordering an Everdrive. We hope to resolve that soon.
Of course, every other payment method is still available for you.