The seed and lemon juice help you stop the avocado from going brown.
The easiest tip is to use the seed. It helps the avocado keep its natural green colour. When you have made guacamole, just leave the seed in the sauce until you are ready to serve the dish. And if you are planning on eating only half an avocado, leave the seed in the other half, cover tightly with cling film to keep out as much air as possible, and refrigerate. Avocados also keep better if you paint the cut surface with lemon juice.
The Keep-it indicator shows the actual shelf life of fresh food, and helps you make smart choices every day. This is how.