Using Visualforce Remote Objects, you can audit whenever a user views a Salesforce record. The audit will show the user’s name and the date they viewed the record. You'll get a related list of record 'views' on the detail page of the record.
All in Apex
sObjects: one weird little trick Trailhead doesn’t tell you
Treating sObjects like a maps with the field name (a string) as the key and the value that is going to be inserted into the field as the value.