Three years ago, Priscilla Elora Sharuk was trying to help her grandmother, who had Alzheimer’s disease, deal with an everyday task that had become frustratingly difficult: remembering passwords for websites and software.

Ms. Sharuk, an architect, told her computer-engineer friend, Antoine Jebara. He then created a USB device that automatically and securely logged on to all the needed computer programs, eliminating the need to remember passwords.

The...