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.
Pushy - Pushy is a reliable push notification gateway for time-sensitive, mission-critical apps.
Gravitec.net - Gravitec.net is a smart web push service that lets you boost subscribers through customizable prompts and automatically target your content to the right audience.
Truepush - Unleash limitless possibilities with Truepush and save up to $600 monthly. Free up to 10K Subscribers on all features.
Pushmaze - PushMaze is a self-hosted Mobile and Web Browser Push Notifications service. It lets you send push notifications 100x cheaper via Firebase Cloud Messaging.
Aimtell - Web push notifications for mobile & desktop