Here is my chart:
Here's how to make your own:
This recipe requires a few command line tools. I'm using Linux, but to the best of my knowledge all these tools are available for Windows and Mac and should work exactly the same way described below. You'll need SQLite (there are several implementations), and GnuPlot.
First you need to extract the weight from the SQLite database in a format that's easy for GnuPlot to parse. Create a SQLite script file. Let's call it extract_weight.sqlite:
select date/1000,weight*0.453592 from weightlog; .quit
Note the "/1000" is to convert the unix epoch timestamp in milliseconds to seconds and the "*0.453592" is to convert imperial pounds used internally in the app  to kg. Run the script and send the output to weight.dat:
sqlite3 wwdiary.database < extract_weight.sqlite > weight.dat
The contents of weight.dat should look something like this:
1379890800 76.2999384291992 1379977200 76.0999346446533 1380063600 75.6999409180908 1380150000 75.5999355651855
# GnuPlot script to plot weight in format # uuuuuuuuuu ww.w # Where uuuuuuuuuu is the unix epoch time in seconds # and ww.ww is weight (I use kg, but use what you like). # # Joe Desbonnet, email@example.com, June 2014. # set xdata time set timefmt "%s" set format x "%m/%Y" set xtics font "Arial, 10" set title "Weight Loss Curve" set xlabel "Time" set ylabel "Mass (kg)" set grid set key off set term pngcairo size 800,400 set output "weight.png" plot 'weight.dat' using 1:2 with linespoints
And now run it:
gnuplot weight.gpAll going well, you should find a PNG image file called weight.png in the same folder with your weight chart.
In part 2 I'll show you how to apply a smoothing filter to the chart.
 There is a subscription service available where a chart can be viewed on an online dashboard.
 Oh please if you're designing software use SI (metric) units under the hood. Convert to antiquated Olde Worlde/American units at the user interface if you must. Even the Apollo moon avionics software from 1960s USA calculated in SI, converting to feet, furlongs, hundred-weight etc only at the last second at the user interface. (See http://dodlithr.blogspot.ie/2011/10/apollo-guidance-computer-agc-software.html)