How many products can I watch — and what happens when I hit the limit?

Up to 5 products at a time, per user (each person's limit is their own — one family member's watches don't count against another's). When you're already watching 5 and try to add a new one, the app will let you know you're at the limit and ask you to remove one first. Removing a watch stops its alerts and takes it off your list right away — if it was an accident, you get a few seconds to undo. Removing something doesn't affect the product or anything on Amazon; you can always watch it again later by pasting the link fresh, and its price history will still be there.