What are some alternatives?
When comparing Roost and PushAlert, you can also consider the following products
PushCrew - Push Notifications for Websites
OneSignal - Customer engagement platform used by 800K+ developers; the fastest and most reliable way to send push notifications.
Pusher Push Notifications API - Send push notifications programmatically at scale
PushOwl - Re-engage website visitors with push notifications
iZooto - Engage your mobile and desktop web users with intelligent web push notifications.
Wise Notifications - The only solution to send notifications to your iOS website visitors, without creating an iOS app yourself. Increase your revenue by retaining your valuable website's iOS visitors. All other web push notifications are missing this. Setup in 5 min.