Background: Older adults, especially those living with cognitive impairment, can experience prospective memory challenges that affect their ability to manage day-to-day tasks, maintain their health, and sustain relationships with friends and family. Although voiceactivated assistants (VAAs) are hands-free, convenient tools with the potential to support prospective memory, there are often barriers to the adoption of VAAs by older adults. Objective: To address barriers to the adoption and use of VAAs by older adults, we developed a tip card to facilitate the use of a VAA to support everyday prospective memory tasks and evaluated the usability of the tip card. Method: The tip card was designed with a human-centered design approach, incorporating the input of a subject matter expert on memory challenges, and provided guidance on how to use the device to perform three PM-related tasks: setting reminders, creating lists, and setting timers. Then, 15 older adults (4 with and 11 without probable mild cognitive impairment) were given an Echo Dot device to use for a 10-day period. Usage logs were extracted from the devices and each interaction was coded according to its purpose. Results: Using the System Usability Scale (SUS), scores for the device and tip card were both "A" on average, corresponding to a rating of "excellent." Prospective memory-related tasks made up 68% of the total uses of the VAA. Conclusion: Taken together, these findings support that VAAs, with the help of a tip card, can help older adults with diverse cognitive abilities complete daily memory-related tasks.