Covve is designed to automatically synchronize with all available contact groups on your device, so in order to have contacts from your social profiles in Covve you need to firstly add those accounts on your mobile phone. Unfortunately there is no direct way of syncing Linkedin Connections with Covve, so you will need to export your contact list from LinkedIn and import it into your address book (e.g.Google Contacts, iCloud or Outlook)
Regarding updating info from Social networks note that Covve scours the web (including LinkedIn, Facebook, Twitter and another 100 sources) for any publicly available information about your contacts. It assembles and curates this data (profile pic, country, company, industry, job title, social network) and adds it to your contacts as required in the form of suggested Improvements. You can review them in the ‘Improve’ tab of the app. This feature works best when your contacts have email addresses.