Log file viewer of Abbott's Freestyle Libre - a CGM (Continuous Glucose Measurement) device.
After realizing that I am prediabetic (HbA1c 5.9), I needed to lower my average glucose level so I wanted to know what kind of activities and foods affect my glucose level by how much and how long.
However, The analysis and display functions provided by the Abbot's web site (libreview.com) and the smartphone app were not satisfactory - the resolution of the glucose plot is too low and the annotations I made are hard to relate with the plot.
Luckily, the libreview.com has a data export function which provides a CSV file with all the information including the annotated text and the glucose values measured by 15 minutes interval.
It's a web app - you can just upload your CSV file on my web site.
Or, if you have a web site, you can run your own. All you need is to deploy a couple of javascript files.