DeepSearch will not access any sensitive data on your device by default. If ‘Contacts’ search is enabled it will have access to the details stored in the Contacts app on your device, such as contact name, phone number, email, company information etc. Only data added to your Contacts will be readable. Data stored elsewhere on your phone, including other apps and settings that might be searchable through the app cannot be read. Going to Settings->Search in the DeepSearch app and disabling ‘Contacts’ will deny the app any access to sensitive information.
The information gathered is solely being used to present back to you while searching in the app.
While the ‘Contacts’ option is enabled, you can search for your contacts directly in the app without opening the Contacts app, using email, phone number or contact name. No data will be sent or stored outside your phone, or used for any other purpose than the above described. No third-party will have access to the information.