9. The phone's firewall
Bubble → Firewall cuts the internet (Wi-Fi and mobile data) of apps on your normal phone. It is meant for system apps that phone home and that you do not use (for example Device Setup, DeviceLock Controller or SIM Manager), but works for any app.
Use it
- Turn on Phone firewall.
- Tick the apps that must lose their internet. Use the search box; Your apps and System apps are listed separately.
- Tap Save.
Turning the switch off lifts every rule but remembers your list.
How it works, and its limits
The phone's firewall does not use a VPN (Play Store can take a VPN down; it cannot touch these rules). It combines three layers, applied by the engine:
- A kernel firewall chain that cuts the app completely. It is lost at every reboot; the guard puts it back.
- Background data blocked on metered networks, with every saved Wi-Fi network marked as metered, so it applies on Wi-Fi too.
- The guard, which re-applies everything every minute while it runs.
Limits:
- After a reboot, until Bubble has Wi-Fi and restores the rules, a blocked app can use the network. Background data stays blocked from the start only if you also turn off Settings → Apps → [app] → Mobile data & Wi-Fi → Background data once by hand.
- The rule is per app, across spaces: blocking an app on the normal phone also blocks the same app inside the bubble.
- Blocking SIM Manager prevents downloading or managing eSIMs while it is blocked.
- Separate Wi-Fi and mobile data choices exist only inside the bubble and the Meta space for now, not on the normal phone.