Reminders
It's easy to mean to save something and then never get to it. Reminders give you a recurring nudge, and answering one is as simple as replying to an email.
A nudge on your schedule
Set up a recurring reminder and Rewindior emails you when it's time, as often or as rarely as you like. It's a small nudge to catch the thing you'd otherwise let slip.
Reply straight into your capsule
When a reminder lands, just reply to it. Your reply, photos and all, goes straight into the capsule, so answering the nudge and saving the memory are the same step.