With some hackerspaces the app doesn't load the JSON.
For example if I test the hackerspace breizh-entropy I have :
"Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://breizh-entropy.org/spaceapi.json. (Reason: CORS header 'Access-Control-Allow-Origin' missing)."
With the same JSON and an other app (myhackerspace on fdroid) the JSON is loaded :).
sent on the move. apologies for typos.