To begin recording your day, navigate to the "New Session" page and press the big, circular button.
The screen that you should see now should look like this:
Lock your phone by turning the screen off. Put your phone in your pocket and make sure that it's not buried in your clothing. You want it in an outer layer of clothing so that you can record the strongest GPS signal possible. The four bars on this record page show you how strong your GPS signal is.
When you're done skiing, press the circular pause button. You should see two buttons, "Resume" and "Send" pop up. Press "Send" to process your data.
The next page you'll see allows you to add a picture and a comment. You can add a picture by tapping on the large camera icon. This image will be used as the background for your sessionsheet and makes it more fun to share your day + easier to find that day later. You can also choose to share on Facebook and Twitter with this page.
After your data has uploaded, you should get a notification letting you know that your day has been processed. You should now head to the Profile page to see the stats for your visit.
You can find instructions on how to use the Profile page here