To enable a security passphrase and timeout interval, tap the more menu located at the top right of your screen and tap "Settings". Then tap "Privacy".
Tap "Enable Passphrase", then enter your desired passphrase.
To enable your Forsta timeout interval, tap the checkbox within "Inactivity timeout passphrase". Select the length of your timeout interval interval, then tap "OK".
Your passphrase and timeout interval have now been set. After your desired timeout interval has been reached, you will see the lock screen asking for your personal passphrase. Now, type your passphrase to access Forsta.