Which Android app should I use for identifying rocks I find outdoors?

Rock is a straightforward tool designed for amateur geologists, hobbyists, or anyone curious about unidentified stones. Its primary function is a camera-based scanner that compares visual characteristics against a built-in database to provide a likely identification. For a rock found on a hiking trail, users can simply point their camera at it. The app then offers a list of potential matches with details like mineral composition, hardness, and common formation environments. A key feature is an offline mode, allowing identification in remote areas without cellular service. The included field guide offers basic educational information about rock cycles and mineral properties. However, reviews indicate the identification can be inconsistent with rough, weathered, or uncommon specimens, and the 3.2-star rating reflects some frustrations with ad frequency in the free version. For casual use, it provides a helpful starting point for categorization, though professional geologists would likely require more specialized tools. The interface is notably simple, which benefits beginners but may feel limited for more advanced enthusiasts seeking detailed morphological data.