Yeah it is a really useful tool for steemit users to protect their account!
I tested with some phishing domains, and it worked correctly

Be careful with those phishing domains:

• steewit(dot)com
• śteemit(dot)com
• ŝteemit(dot)com
• şteemit(dot)com
• šteemit(dot)com
• sţeemit(dot)com
• sťeemit(dot)com
• șteemit(dot)com
• sleemit(dot)com