Geometry Stash is a free iPhone application developed by Anson Liu, designed to be a comprehensive guide for geometry enthusiasts and students alike. The app allows users to easily access a wide array of theorems, postulates, and corollaries with just a swipe. Users can create custom slides with drawing commands and share them effortlessly with others through various platforms like Airdrop, iCloud, and more. Geometry Stash also offers features like iOS Spotlight Search integration, Slide Over and Split View support, iCloud Drive access, and the ability to export slides in different formats for enhanced portability.

Geometry Stash has garnered positive reviews from various sources, praising its functionality and usefulness as a mathematical reference tool. With features like custom slide creation, guided access for learners, and bulk import capabilities, Geometry Stash aims to be a valuable companion for geometry studies and reference needs.