Aware stores a maximum of three thoughts at a time. Each has a time limit. When the time runs out, the reminder remains in the shade until you mark "Done" or extend it.
It's not a to-do list. It doesn't have an account, cloud, or feed. The buffer lives on the device: widget, New shortcut, persistent notifications.
Free: 3 slots, 20 minutes, "Done" clears space.
Aware Pro: Memory file with restore, and duration of 15 / 20 / 30 / 45 / 60 minutes.
Made for Android. Offline.
Three slots. One clock. Working memory, not a to-do list.