User notifications

[JudahGabriel]

Currently, we don't stay in touch with registered Chavah users. When new music or features are rolled out, we don't let users know.

We should build a notification system that lets users subscribe to Chavah news & updates. Subscriptions can be done via email and HTML5 push notifications.

We should automatically send out emails when new music is posted. Alternately, we build an admin tool that lets us craft the email before sending it.

Users should have option in their profile to opt-in/out of email and push notifications.

[JudahGabriel]

We now send a welcome email with a nice intro to Chavah when a user confirms their email. We also overhauled the welcome page to be a little more fun.