i2p Android is generally apache2 but many different components have different licenses. Would check the source. The latest code / versions is on their site, not GitHub or F-Droid (many versions outdated, of course).
I usually would run a separate profile and have the official binaries or one I considered better for each individual network anyways.
It's not so easy to use and integrate with existing software.
the routing system with a lot of device is a nightmare.
I tried it last weekend with nomadnet, 3 PCs located on different subnets and 1 LoRa antenna
I find it hilarious that open source looks and feels like a computer virus, but it has nothing to do with a computer. It's a legal virus. Once the open source gets into you project, it highjacks it and turns it open source, making all projects that work with it, affected too