letgo
let go is the number one sales site for program on phones.
carousell
this is the second best program
varage
nobody uses varage unless they are really forced to
kijiji
kijiji used to be king - i discovered theres an app for this
craigslist
i don't go on craigslist or kijiji. they don't have mobile friendly sites.
ebay
ebay is king.