ShapeShift and Changelly are lightweight exchange services supporting many kinds of alt coins. But I wondered which provides better exchange rate? Thus, I made a web service which compares exchange rates of them.
Open https://trapezacoin.netlify.com and choose deposit and receive currencies, then it shows current exchange rates! You can also go to ShapeShift and Changelly directly by clicking the exchange button.
This service is still beta version and if you find bugs please write a comment :)