It appears that Apple may be working on adding service workers support to WebKit. The WebKit Feature Status webpage has recently been changed from "Under Consideration" to "In Development." This change may be an indication that Apple will eventually support Progressive web apps (PWAs).
GitHub has rebuilt its desktop Git app from the ground up and has released the new GitHub Desktop Beta. The company also released the GitHub package for Atom which allows users to perform common Git operations from within the editor such as stage whole files or individual lines, and create commits.