What does it display ? What can I do ?

The contacts screen and leads screen display lists of recently viewed records form Salesforce, and allow you to log information and create new ones. Here is what you can do:
1. Search your contacts/leads
While the app shows you first the recently viewed redords, you can search all the existing ones in Salesforce. Simply tap the search area and type the name of your contact. Note that the search won't be able to work properly if you have bad network.
2. Contact/lead row
Press Call to initiate a call to the selected person. If the call lasts more than 45s, the app will automatically offer you to log it.
Simply tap the row to access the detailed information.
3. Add new contacts/leads
the shortcut button lets you create a new record. Here is an example of how to create a contact using Zero Keyboard
4. Refresh
the refresh button lets you synchronize the recently viewed records from Salesforce.
This is it! That's all you need to know about this screen, but you can learn more about the details view.