I have running GCM solution. Will port it to Firebase the next weeks -> be patient, it's summer

and post a tutorial. Like everytime I prefer php instead of RDC.
The solution
could be:
- device/user has to choose the scores/teams he's interested in
- the chosen content is handled in a database (like in FB someone is "following" a person or here a thread)
- if new content is created which the device/user follows, via Firebase the device gets a message
- to get the content
- display the message (like "Real Madrid scored against Bayern München 2:1")
- a simple httpjob is started to get the content (like a new scoreboard)
Benefits:
- you can use Google servers for the messages an another to do the db stuff
- all devices just register and wait for messages (Google - for free)
- no messages = no database/server load

- you can handle it (like 100 devices get messages per second)
- so the server/db will not crash
- you can use b4j to handle it (if you are able to run it on the server - otherwise just use php)