Two counts would mean that police have reason to believe the accused had been involved in activity that he contributed to the cover-up on (minimum) two separate occasions after the murder.
This could be:
*The acquisition of the phone knowing that it belonged to the victim-1st count
*Operation of the phone- 2nd count
This would not have happened prior to the murder as the charge is 'after the fact'.
Someone mentioned that the accused could have 'found' the phone. This is unlikely given the charge. If the accused had found the phone AND willingly operated it KNOWING if belonged to the deceased. The charge would be Attempting to Pervert the Course of Justice. Which, by the way, would be a lesser charge that could later be laid if the accused cooperates.
For the police to know who it was that used/was in possession of the phone likely means that someone has provided that information. I would assume that either JW or TB has started the revelation process. If this is the case we most likely can expect more information to be released in the weeks leading to the hearing as more information is offered up.