In order to keep your Orkut account safe in mobile, it's important to follow a few tips, just like in your computer:
Keep your device updated
Your carrier provider or the device's manufacturer may send you a software update. Additionally, some devices allow you to install third party applications that also need updates from time to time. Updating both the operating system and applications to the latest version is a crucial step to keep your account safe.
Lock your device
Most devices allow you to lock the screen. A password is required to unlock it again. This can be very useful to avoid people that - inadvertently or not - might access your phone and see your personal information.
Don't share your device with anyone who wants to access his/her account
Sometimes, a friend or relative can ask you to use a device you own in order to access his/her own account. While it's ok to show your device or application to them or even teach your mother how to do stuff on her cell phone, avoid exposing your personal information, since most of them don't require entering username and password again.
Don't access your account from someone else's device
Some devices can store information like cookies, passwords as a convenience to its owner. Note that when you are using someone else's device, your information can be stored too. Only access your account from a device you own.
Have 2-step verification enabled? Do you own an Android, iOS or Blackberry device? Install Google Authenticator
Google Authenticator is a mobile application that allows you to generate 2-step verification codes on your smartphone without a network connection. We recommend users with smartphones to use Google Authenticator to generate verification codes instantly to sign in to their Google Apps accounts.