A quick note to users (using harmattan devices).....

Google now also provides currency info, but somehow Google doesn't let users add currency symbol into a Google portfolio for tracking. Stockona+ has Market Overview to show the currency info, but currently the currencies covered are limited.

I just found out it is possible add currencies into a local portfolio so you can add currency rates that you are interested in. Here's the how-to:

1. When creating a symbol, type in the currency symbol you're interested in, e.g. USDCNY.
(Unfortunately you cannot rely on the search button to help you find the symbol name since Google Finance's search doesn't search into currencies...)
2. Type 'Currency' in the exchange field.

There you go now you can track any currency rate that Google provides!