if you looking for free bots for agar.io game then op-bots.com will be best option for you.If you want more bot then you can buy coins and via coins get bots.But for everyone 5-10 bots are free for always.
web adres for op bots: www.op-bots.com
go website
register your name
get extention for chrome
go agar.io see your bots.