Firebase Cloud Messaging provides a reliable and efficient connection between servers and devices, allowing for the delivery and reception of messages on mobile devices. This cross-platform messaging solution lets app developers reliably deliver messages to app users at no cost.
gRPC is a modern open source high performance RPC framework that can run in any environment. gRPC connects services in and across data centers with pluggable support for load balancing, tracing, health checking and authentication.
RestKit is a modern Objective-C framework for implementing RESTful web services on iOSand Mac OS X respectively. RestKit provides a powerful object mapping engine that seamlessly integrates with Core Data and a simple set of networking primitives for mapping HTTP requests and responses built on top of AFNetworking.
Firebase (Cloud Storage) is a powerful and simple object storage service built for Google scale. It adds Google security to file uploads and downloads for Firebase apps. Developers can use it to store images, audio, video, or other user-generated content.