1. reCAPTCHA is a free security service that protects your websites from spam and abuse.

  2. Akismet is a spam fighting service that protects millions of WordPress sites from comment and contact form spam.

  3. Free Caller ID & Call Blocker app that allows mobile users to block phone calls, identify calls, blacklist unwanted callers and much more.

  4. UniqPin is a free for non-commercial use service which destiny improve ability of interfaces detect...

  5. Find a person by a name or phone number worldwide for free using Truecaller.

  6. Confident Technologies provides free CAPTCHA security software called Confident CAPTCHA, a picture...

  7. WhosCall is a reliable caller ID app whose popularity has led to its adoption by many users including international media. You can now manage the numbers calling you regardless of whether they are part of your contact list or not... read more.

  8. A plugin to make the process of creating a negative captcha in Rails much less painful

  9. Mollom is a freemium web service to get rid of spam, unwanted content and fake users on your...

  10. SME

    Search over 1 Billion phone numbers worldwide. Identify unknown phone numbers and block unwanted calls.