You've Got Spam - A new tool that lets you spam back the spammer
unscan - Scanning of user-submitted content made simple.
Callwarden - Go to war on spam calls 📵
Castle - The easiest way to protect your users from getting hacked
OOPSpam Anti-Spam API - The better, new standard to stop spam content.
Crypton.sh - SMS - Secure Anonymous SMS in the cloud (and a phone number)