Best free social media bots?

Does anyone have any recommendations for free bots for Twitter, Pinterest, Tumblr, or Facebook?
There seems to be a couple out there but I'm not sure what's best.

Thanks in advance

When it comes to social media always better to pay! Social media companies are making updates all the time so any "free" bot will probably stop working after a week or will get your accounts suspended. If you do find free ones test them first but not with your main accounts.