The screen can be off when recording so as to not give anything away, so placement of your Android device can look natural or completely hidden, depending on what the job calls for.
When you're ready to view your footage, simply swipe right in the app to access the menu panel, then select "Recorded Videos." You can also see what you have scheduled to record using the "Recording Jobs" option.
If you want your Ustream channel for your eyes only, make sure to make it private and password protected.
Once you have your account set up, the spying can begin. If you're going to catch your roommate snagging your Cheetos, place it somewhere in the kitchen that isn't so obvious—obviously.
Keep in mind that your i Phone has limited battery power, so it won't be able to take videos all day long without some plugged-in juice, so make sure you choose a place near an outlet.