TradingView

TradingView runs in the browser and in its desktop app; both work the same way. Everything here works on the free plan.

Way 1: the Fib Retracement tool

Draw it on a locked box

1. Open the chart of your market. Switch to the box’s own time frame first (for a monthly box, choose 1M) so you can see last month’s candle as one bar, and note its high and low.
2. In the left toolbar, open the Fibonacci group (the icon with stacked horizontal lines) and choose Fib Retracement.
3. Click on last month’s high, then on its low. Do not worry about precision yet.

Enter the ladder’s values