I need a good Twitter Follow bot

Hi i need a good twitter bot that will follow people for me. There any many on the web but i don't want a random one. i want a good one and one that is tested and works good. I can pay you $10 for the download if its free but if its cost money and its under $35 then i will give you a $10 referral if its a legit. so far a have dopebotz so dont send me that one or tweepi