街野植物図鑑　400種版 is a free educational and reference app available for Android. Developed by 有限会社　グリーンシステム, this app provides a collection of approximately 400 plant species commonly found in Japan's coastal areas and low mountain regions (up to around 500 meters above sea level). The app includes simple descriptions and photos of the selected plants.

The focus of the app is on outdoor plants, but it also includes plants that have been planted by humans. However, it does not include non-flowering ferns and mosses. The 400種版 version of the app allows users to search for plants based on basic characteristics. The plant listings are arranged in alphabetical order according to their standard Japanese names.

It's worth noting that despite the relatively small number of species, there are many search criteria available, which can sometimes make it difficult to find specific plants. For those who want to explore more plant species or feel that 400種版 is not enough, there is a paid version available with 1200種.

Overall,街野植物図鑑　400種版 is a useful and informative app for anyone interested in learning about the diverse plant life found in Japan's coastal and low mountain regions.