They use it in android. They also use it in their firebase sdks for ios/android. Nanopb doesnt solve wire issues. Thats for you to solve by designing your data

They use it in android. They also use it in their firebase sdks for ios/android. Nanopb doesnt solve wire issues. Thats for you to solve by designing your data better. Nanopb solves your applications binary size getting needlessly huge, due to less bloated code-gen and saner runtime (if you have to use protobuf, or are already married with it that is). It also gives more control over memory management, which is especially important for embedded.