Contacts menu lets you browse the web phone book i.e. Web contacts and your mobile contacts synced with your mobile phone.
To synchronize mobile contacts and upload them to the platform a user has to allow for this either during the first start of the mobile app or later from the Settings\Sync contacts menu.
If you upload the contacts you can at any moment remove them by ticking off the sync contacts option in the mobile app settings.
Both the web and mobile contacts are private – only the user created or uploaded them will see them.
You can choose which contacts you want to see by clicking the filter box under the Search field. The default option is All. You can expand it and you will see the Web contacts and list of your devices. If you did not allow the mobile contacts to be uploaded from your mobile app the contacts list for the device will be empty.