If you're looking for a BirdWeather alternative, Pl@ntNet is worth a look. It's a citizen science project for identifying plants with AI-powered image recognition technology. The mobile app lets you participate by reporting observations that the community validates to improve AI results. The project can help you understand biodiversity and conservation by participating in community-collected data.
Another alternative is PlantIn. It's designed for plant enthusiasts and offers AI-powered plant identification by scanning images or searching a database, disease diagnosis with expert assistance, personalized care plans and a forum for discussion. It promotes sustainable practices and offers educational content, so it's good for casual enthusiasts and pros, too.
Although it's not directly comparable given its broader scope, Google Lens is a useful tool that can identify objects for plants and animals. It uses your phone's camera to visually search and provide information on things in view, which can be useful for a quick, convenient species ID.