At Automattic, we have a saying:
In this spirit, we are announcing today that all of the official Simplenote client apps are now Open Source Software under the GPLv2 license. In addition to the previously open sourced Electron app, you’ll now find the source code for the iOS, Android, and macOS applications on our GitHub page.
We love using Simplenote at Automattic and hope that we can build a great community of contributors from around the world to help make the apps even better.
You can download the source for the apps here:
– The Simplenote Team