[Feature Request] Add Per‑App Routing (Allowed/Disallowed Apps) to ZeroTier Android Client

[rzxas]

Hello! Thank you for your great work — ZeroTier is an outstanding SD‑WAN/VPN platform, and the Android client is stable and easy to use.

I would like to request a feature that would significantly improve the Android client:
per‑app routing (allowed/disallowed applications).

• Why this is important
  Currently the Android client forces full‑tunnel behavior: once ZeroTier is enabled, all applications route their traffic through the virtual network. This is often unnecessary and creates several limitations:

  • Users cannot choose which apps should use ZeroTier
  • Some apps need local Internet access while others need ZeroTier
  • Full‑tunnel increases bandwidth usage and battery consumption
  • Administrators cannot deploy ZeroTier in environments where only specific apps should access internal resources

Android already supports this
Android’s VpnService API provides built‑in methods:

addAllowedApplication()
addDisallowedApplication()

These allow VPN apps to implement split‑tunnel on a per‑application basis.
Many VPN clients already use this mechanism successfully.

• What would help
  Adding a simple UI in the Android client:

  • “Allowed apps” — only selected apps use ZeroTier
  • “Disallowed apps” — selected apps bypass ZeroTier
  • Or a toggle: “Use ZeroTier only for selected apps”

This would make ZeroTier much more flexible on mobile devices.

• Why this matters
  Android devices are often used as lightweight remote terminals or secure access points to internal services. Per‑app routing would allow ZeroTier to be used in professional environments where full‑tunnel is not acceptable.

Thank you for considering this feature!