The first indicator is the RSI. You shouldn't be surprised that one of the best trading strategies combines ADX and RSI signals. Although the RSI indicator is an oscillator and the ADX is a trend indicator, they work well together. Every trader knows that it's easier to trade with a trend, not with a sideways market. As such, the RSI may provide reliable entry points, while the ADX can give signals on the trend's power.
You can also use the index with other trend indicators, such as Parabolic SAR. It's worth choosing indicators that aren't based on Moving Averages. As a reminder, the ADX calculation includes the Exponential Moving Average.