These are the "official" indicators, as provided with ATM out-of-the-box. v3 also gives you the ability to create your own custom indicators, making the possibilities endless.
Most people should require only the standard indicators above. You can however create your own custom indicators. There is detailed help in the wiki. Assistance can also be sought in the forums, along with requests for adding Indicators to the official set. And you can use any of the provided indicators as examples to help you create your own (Detrended Price Oscillator and Pullback, especially, show a range of techniques). Export the example, then import with a different name and modify as you wish.