 Astrophotography mode was introduced with Pixel 4, and backported to the Pixel 3 and Pixel 3a.While the Google Camera software is specific to particular Google hardware, many developers have released unofficial ports that port its newest features to older Google phones and non-Google phones, sometimes enabling features under development not yet enabled by the official app.Because some of the Google hardware's advanced features are not available in other devices, the GCam app has been reverse-engineered and modified to make it compatible with other phones.