: Available on the App Store and MacUpdate . It requires macOS 10.9 or later and supports Apple M1 chips.
: A design tool found at Paper.design for macOS (ARM), Linux, and Windows. DoublePane for Mac Free Download
If you are specifically looking for "Solid Paper" in relation to DoublePane, it appears there might be a mix-up with wallpaper or design tools like or Bumpy Paper . Quick Access & Alternatives : Available on the App Store and MacUpdate
: A dedicated wallpaper app on the App Store that uses real-time Metal shaders for live backgrounds. If you are specifically looking for "Solid Paper"
DoublePane is a window management application for macOS that allows users to quickly position windows side-by-side using keyboard shortcuts. While historically a paid app, it has been listed as on the Mac App Store at various times.
: A free, open-source utility for spreading high-resolution images across multiple displays, available via GitHub or Reddit . News and Tips for Mac, iPhone, iPad, and Everything Apple