Krivo index, suggested by Richard Krivo, tries to quantify the "strength" of a currency by checking how many of its pairs are trading strongly (close above 200sma). As you can see from the chart, KI gives an excellent overview of their strength. Note how it correctly points out the JPY crash (Nov 2012).
I decided to implement KI for each currency separately to be compliant with Pine requirements. Also, this enables to add only the needed currency KI scripts (for ex., just CAD_KI and USD_KI). You can add the needed currency KI scripts and merge them all together to form a chart like this. Make sure you "right click" on all and select "Scale Right" (or "Scale Left". Thing to note is all KIs shd be aligned to the same scale).
I have published KI for only 5 currencies now, but can add more on request. BTW, this index is usable on all time frames.