Awais

Simple Spam Blocker use honeypot technique which is fast and easy way to prevent spam. This plugin can stop spam comments, spam registration and also can be used to stop bots to try to login into admin panel. This plugin also provide option to stop spammers to get register via Ultimate Memeber Plugin’s registration from. You can also use shortcode [simple-spam-blocker] on any form to stop spammers.

Simple Spam Blocker

Simple Spam Blcoker stop spam comments and also can be used to stop bots to try to login into admin panel.

WP-Biz (Ryan)

The “honeypot” technique for SPAM protection is invisible to humans, and tricks robots into filling out an invisible form field. Then, if that invisible field has been filled, the form cannot be submitted. Easy, non-instrusive SPAM protection.
No settings to set, this honeypot is added to all Formidable forms on your site, unless the user is logged in. When SPAM is suspected, the form will not be submitted and the visitor will be alerted to this fact.
Tested to work with both Formidable (free) and <a href="http://www.wpbiz.co/go/forms" rel="nofollow ugc">Formidable Pro</a> (best bet for awesome form power!)
A note to Formidable Pro users: You paid to receive extra features in the Formidable plugin. Me too, it’s well worth it. This Honeypot plugin, and Ryan (the developer) are not connected to Formidable in any way. Since this adds another very helpful feature to Formidable, I ask you to send a <a href="http://wpbiz.co/donate/" rel="nofollow ugc">donation at WPbiz.co</a> to say thanks and encourage future developemnt.

Formidable Honeypot

Add SPAM protection to your Formidable forms without annoying your visitors with Captchas, math, or other fields.

Simple Spam Blocker vs Formidable Honeypot