See my answer above but bots really don't change anything about penny auctions. Most allow for placing multiple bids which effectively automates the auto-bids and does what bots would do but better.

Well, it's "better" in the sense that they may allow things that a bot couldn't realistically pull off, but it's not really better because everyone has access to the tool. The advantage of writing a bot is exploiting a loophole in the system that most people aren't aware of. If everyone has the same tools then it's a fools game through and through, at least for something as simple as penny auctions (Poker is another story obviously).