Fish will generally go gasping at the top of the waterline for air due to lack of oxygen. This doesn't include fish that do this no matter what like common plecos and common cory cats. Keep your tank moderately stocked and you will be fine. If you have enough filtration to combat ammonia and nitrites, then chances are very high you have enough oxygen in the water. Any time you see a huge airstone, it has to do with tanks that are overstocked with large big fish that require high oxygen levels.
So, no most folks do not need an airstone or oxygen reader. You do not need an airstone, you do not need an oxygen reader.