We have an offline surveys app for Windows and Android devices that downloads a copy of the survey so you can collect data without an internet connection. Then, later when you have stable internet, you can sync the data back up to the server so everything is in a central location to download later on.
The offline surveys app requires the survey be authored in Lighthouse Studio and hosting in our hosting system. Previous versions of the software have an offline surveys app but for Windows devices only, and the online Discover platform doesn't yet support the offline surveys app.