OneSignal - Customer engagement platform used by over 1 million developers and marketers; the fastest and most reliable way to send mobile and web push notifications, in-app messages, emails, and SMS.
PushBots - Light SDK for mobile push notifications
Outbound - Generate personalized cold emails with AI
iZooto - Engage your mobile and desktop web users with intelligent web push notifications.
PushCrew - Push Notifications for Websites
Roost - Web Push has 30x better opt-in than email. Increase engagement with your audience using web push notifications