An open source tool for sending push notifications to Android and iOS. Pushkin has two modes of operation: Push Notification mode can issue a direct notification for the supplied user and message. Pushkin will find the device ID for the user and send the message. Event mode can send notifications based on an event - something happening to a certain user. Pushkin will decide whether it should send a notification based on the event, construct a localised message, find the device ID for the user and send the notification. It is also easily scalable, because you can run as many instances as you need with each instance capable of pushing 500 messages per second.