Scan the code
Point a phone camera at it to open the download page. Works from a screen or a printout.
netkeeperapp.com · needs internet to download
Phone to phone, no internet
In the Android app, tap Share NETKEEPER, then Send the app. It goes straight across by Bluetooth or Quick Share, so it uses none of your data allowance.
On the other phone, open what was sent and allow installing apps from there when it asks.
Tap-to-send over NFC (Android Beam) was removed from Android in 2019. Quick Share and Bluetooth are what is left, and both work well at arm's length.
PC to PC
The Windows file is only 41 KB. Send it by email or chat, copy it on a USB stick, or share it over your local network. No download needed.
The receiving PC unzips it and double-clicks Start-NETKEEPER.vbs, as in the steps above.