The OpenDataKit (ODK) platform (2008) allows people to digitize paper surveys, and deploy them easily onto multiple Android phones. Data remains digital throughout the entire workflow, including the creation of the survey, recording of results, and merging of results at a centralized server. This eliminates paper-to-computer transcription overhead and many potential sources of human error. Mission-critical metadata such as on-site timestamps and georeferences, pictures, and barcodes can all be recorded automatically. MobileSurvey provides a back-end for storing data and administering surveys through a web interface.
There are many alternatives out there, such as CommCare, Kobo Toolbox, and FormHub, of which MobileSurvey is a fork. We started with FormHub, but experienced many issues with it, such as the public server usually exceeding its capacity, and the fact that it is offically no longer being maintained. Also, there are many decisions about data structures and overall code quality that we disagree with. Consequently, we made our own fork which has a stronger emphasis on scalability, geospatial visualization, fraud detection, and intercompatibility with other apps that we have been building to support end-to-end data analysis.
Surveys are specified using the XLSForms standard, applied to Excel spreadsheets. This format for describing surveys allows users to encode datatypes, checks, conditional logic, and basic algebra, all in a spreadsheet. You can learn how to translate your surveys into the XLSForms standard here.