Lark tracks your daily walking, running, biking, and stationary periods. Additionally, you can add "workouts" to accommodate other physical activity that Lark might not pick up from your phone's sensors. By tracking the stationary period of your phone between putting it down before bed and picking it up in the morning, Lark also gets an estimate of your sleep patterns.
Additionally, if you have a steps counter that doesn’t sync directly to Google Fit (Android) or Apple Health (iOS), or doesn’t allow other apps to access the data that it sends to your phone, you may need to change your permissions or manually enter that activity for Lark to count it.