Sleep as Android is a popular app for logging sleep. Data stored on the app’s SleepCloud service can now be analyzed on zenobase.com.
The data includes begin and duration, percent of time spent in deep sleep, rating (if any), and the number of “sleep cycles”.
The simplest way to get started is to create a new bucket, choosing the Sleep (SleepCloud) template.
Caveat: SleepCloud trusts any app that has authenticated you with Google. This means that any service listed on Google’s Account Permissions page has access to your sleep data. (fixed as of April 27)