The best alternatives to isitphish are Phishero, Phishbert, and PhishDeck. If these 3 options don't work for you, we've listed a few more alternatives below.
Phishero is a simple and low-barrier-to-entry phishing simulator. Designed for organizations of all sizes, Phishero gives you the tools to quickly deploy a phishing simulation to test your organization's resiliency to phishing attacks.
A Slack bot that monitors and automatically removes messages that match a set of given regex patterns (Ethereum addresses and Etherscan.io links by default, but you can extend this easily yourself). Set this up in your cryptocurrency or ICO Slack instance to automatically moderate potential phishing or scamming attempts.
PhishDeck makes it easy to simulate advanced realtime phishing attacks to improve and measure your security awareness program. It features ready-to-use phishing simulation templates, reports and actionable insights all with simple, transparent pricing.