Text notification, e.g.

ALERT

This might pop up on your phone when there's an urgent message or reminder waiting for your attention.

This clue is a straightforward definition where "Text notification, e.g." hints at something that grabs your attention, like a pop-up or warning. "Alert" fits perfectly because it’s a common term for notifications on phones or computers that signal incoming messages or updates. The "e.g." suggests it’s one example of many, but "alert" is the most concise and direct answer. No wordplay here—just a clean match between clue and solution.