at.market - at.market has more than 1000 domain names where you can get the email you've always wanted.
One Word Domains - Database of all available one-word domains
aliveDomain - aliveDomain is a complete domain monitoring platform that tracks the expiry dates of domains and sends notifications through Zapier, Telegram, Slack, Discord, Webhook and Email.
Domainz.io - Premium domains, for not so premium prices
Bye Bye Domain - Buy and sell domains before they expire
Undeveloped - Domains you never thought were available