Fredo: press many devices at once (groups)

1. Open Groups › New group, name it (e.g. All office PCs) and tick the devices.
2. Tap Press all — each device receives the command on its next check-in (about every 20 seconds) and the page shows the progress.
3. Groups can also be scheduled or pressed from the API with group_id.

Devices do not need to be on the same WiFi.