As a follow-up on the idea https://planet4.greenpeace.org/idea/browser-p4-push-notifications/ - we should investigate the plugin https://onesignal.com/ - which allows browser notifications.

GP Spain used this plugin in the past, getting a 4-5% conversion rate - it's free up to 30k subscribers, after that it looks like it gets expensive. It's not using popups, it's a browser thing that pops up via HTML5 I guess, and admins seems to be able to ask that question ("would you like to receive notifications" ) after people spent some time on the website, not when they first load it."

Review should include:

• full functionality matrix
• security review according to our P4 process
• price and permissions model
• GO/NO Go recommendation from a technical Point of view
• gap analysis in case we need to customise it
• eventual concerns about "non-logged in" notification-based and user privacy

This functionality could be connected to both "Challenges" and "Follow" feature..