The case of R v Tannhauser involves the use of a cell phone app that prevents making a cellular phone call while driving. Initially Mr. Tannhauser's defence was successful after receiving a distracted driving ticket but it did not survive after examination in the BC Court of Appeal.
Patrick Tannhauser was driving on the Trans Canada Highway approaching the Helmcken overpass in View Royal. He was stuck in what is known locally as the "Colwood Crawl" at 8:35 am. Mr. Tannhauser was holding his company issued cell phone at the top of the steering wheel.
The Capital Regional District Integrated Road Safety Unit was operating a check for phone use with an observer near the overpass. He observed the cell phone, radioed the pickup team and Mr. Tannhauser was flagged over and issued a violation ticket.
The company that Mr. Tannhauser worked for had installed an app on the cellphone that prevented it from being used when it was in motion.
He disputed the ticket on the ground that he was not using the device within the meaning of the legislation because the app prevented him from doing so.
Judicial Justice Gordon agreed and dismissed the charge.
A subsequent case in traffic court, R v Movassaghi, saw the driver try to use this decision as a defence at his trial. Judicial Justice Adair ruled that Judicial Justice Gordon's interpretation of simply holding the device as not being ‘in a position in which it may be used’ was not correct and convicted Mr. Movassaghi.
An appeal to the BC Supreme Court found Mr. Justice Johnston agreeing with Judicial Justice Gordon. He upheld the ticket's dismissal.
Crown turned to the BC Court of Appeal. Chief Justice Bauman wrote the following:
 This appeal raises two issues. First, is a cellphone with no immediate functionality an “electronic device” as defined in s. 214.1 of the MVA? Second, can a device with no immediate functionality be held “in a position in which it may be used”?
 I would answer both questions in the affirmative. As I will explain, neither provision of the statute incorporates cellphone functionality as an element of the relevant definition. Thus, the disabling software in question cannot form the basis for a successful defence.
The moral of the story still seems to be that if you are driving leave the phone alone!