Anyone have an Android VPN app that automatically routes specific app communications through that VPN - without always turning on/off the VPN app?

thus...

VPN app is always 'on' but doing nothing until the user opens specifically defined mobile apps or specifically defined web sites, all that traffic is routed through the VPN... but none of the other traffic is?

Hi, I used to use OpenVPN but it wasn't automatic or pretty. I was just about to try it with Tasker when I read about ZeroTier. You set up a free account and then add the devices you want (Don't forget to "enable" each device in the online control web page). It basically adds a virtual LAN between your devices even if they are far apart. VERY simple to set up and use.

Edit: In the BI5 Android app, the LAN and WAN are both set to the ZeroTier IP address of the BI5 server with your BI webserver port (81 in my case).

<Your ZT IP>:81

In BI5 main settings/ Web server, the LAN address is the normal local LAN IP (no change), but the WAN address is empty, as your remote (or local) android device is now connecting via a virtual "local" LAN.

It just works. At home or away

With the ZeroTier solution is there much of a lag in the video playback or live stream?

Not that I had noticed. I haven't measured it though.

I've actually tried using a VPN setup like you're describing, but found it wasn't the best solution for me. The main issue was the performance hit; even though the VPN was supposed to be passive until needed, it still caused some lag on my device, and not all apps worked smoothly with the VPN's selective routing. I switched to using mobile proxies instead, which seemed more flexible and lighter on system resources.

With proxies, I found it easier to configure specific rules for app or website traffic without affecting the rest of my device's connectivity—less hassle and better control. If you're exploring alternatives, you might want to check out https://proxys.io/en/buy-mobile-proxies. They offer a variety of options that could fit what you're looking for.

For me, the simplicity of ZeroTier was worth its weight in Gold after struggling with setting up OpenVPN. No more turning OpenVPN on before the BI5 app when reviewing remotely either; just open the BI5 app wherever you are and it works.

Tailscale does this well. It routes only traffic that matches the VPN IP address of your Blue Iris server, leaving other traffic alone.