In our digitized world, we increasingly rely on technology for remembering. Personal Knowledge Management Applications (PKMAs) help us save and organize relevant and worth-remembering digital information. Thus, PKMAs serve as an external memory prosthesis but with the innate risk of substituting our organic memory. Our results from an online survey (N = 58) on user motivation for PKMAs show that users rarely revisit their digitally saved content. As a result, any memory about previously obtained knowledge naturally attenuates over time. However, being able to recall from one's organic memory is pivotal for creative processes such as brainstorming and the successful integration of new information. We propose endowing PKMAs with a memory-augmentation feature that periodically reminds one (e.g., on one's mobile device) to revisit stored content for counteracting long-term forgetting. Periodic revisiting may consolidate the memory recall of the stored information, and thus the memory about saved information becomes gradually augmented. To address the specific requirements of reminders in PKMS, we conducted a follow-up focus group (N = 7) to discuss potential design features, in particular in regards to timing and presentation format. Ultimately, we elicit a set of design principles for future PKMAs that support memory augmentation.