This is known as transactive memory. It may be a person or a device. In the case of injury, reliance on devices may be preferable to reliance on other people. In the uninjured, does such reliance weaken memory? Cyborg Anthropologist Amber Chase has a few words to say on this. That job title must raise an occasional eyebrow at Passport Control.
One person’s dependence-inducing device is another’s gateway to research freedom. 15-year old Jack Andraka researched much of the background to his groundbreaking pancreatic cancer detection device on a smartphone en route to school.
Issue 2885 of New Scientist (6 Oct) has an 11-page feature on memory, which encourages you to ‘forget everything you thought you knew’.