ArcGIS Survey123 is a free data collection tool developed by Esri for iPhone users. This app allows users to capture reliable data from their familiar devices, either online or offline. By publishing surveys to ArcGIS Online or ArcGIS Enterprise, users can securely upload data to ArcGIS for further analysis.

One of the best features of this app is the ability to collect data with smart forms. This allows users to create intuitive and easy-to-use forms that can be customized to fit their specific needs. Additionally, Survey123 allows users to attach photos to their surveys, which can be incredibly useful for visual documentation.

Another great aspect of Survey123 is its ability to work both online and offline. This is especially helpful for users who may be collecting data in areas with limited or no internet connectivity. And once the data is collected, users can submit it directly into ArcGIS for further analysis.

Lastly, Survey123 supports the use of high-accuracy GNSS receivers. This can be incredibly helpful for users who need to collect precise location data.

Overall, ArcGIS Survey123 is a powerful and versatile data collection tool that can be incredibly useful for a variety of applications.