One of the reasons the Facebook app was large was that they were using Thrift or something and generating a tremendous amount of code for their API interop. Pro

One of the reasons the Facebook app was large was that they were using Thrift or something and generating a tremendous amount of code for their API interop. Protobuf+GRPC is similarly heavyweight, so I wouldn't be surprised if some megabytes were dedicated to the generated code. But hundreds of megabytes is wild. It has to be one-package compatibility as opposed to specialized app packages for different form factors etc.