Many apps used by smartbands/watches have no option to export your personal data, so you can't process/visualize, store, or migrate to other app.
Also I know that some fitness apps for android apps allow the data export to external files as excel, such as Withings healthmate can sync data with its "cloud/server" and from their webpage you can export data to excel.
For Dafit and other fitness apps with export/import :
Do you know apps/options/methods to extract its data?
Do you know apps to process/convert data from different apps ? /convert this