The FillUp application does not knowingly collect or store personal data.
Internally, FillUp uses the AndroidPlot library for creating statistical plots/charts. To the best of my knowledge, AndroidPlot also does not collect or store personal data. Visit their site here for further information: http://androidplot.com
If you installed this application from Google Play, then Google Play does collect some personal data. Please see the privacy policy for Google Play Services here: https://policies.google.com/privacy