TrailDex Android app turns nature walks into collectible card game

TrailDex is a new Android field guide game that encourages users to notice nature during walks. It generates collectible cards featuring local wildlife and plants, complete with haikus and simple game stats, based on user observations. The app uses open-source mapping and routing services, avoiding proprietary map APIs and fees. It employs the Gemma 3 AI model via Ollama for optional photo-based suggestions, running on a user's own computer rather than a cloud service. All collected cards, notes, and GPS tracks are stored locally on the device without requiring an account.