The apps interface is slick and provides a lot of information at a quick glance. The sunrise/sunset ring is a nice touch (no pun intended). It definitely feels like it was made for a small touchscreen mobile device, and not just a shrunken version of a desktop app or website. The main thing keeping it from being my go-to weather app is that there isnt any hourly weather info available, even on a secondary or tertiary screen.
Also, the apps required access to location services and the network makes it less than ideal for use on an iPod touch. Its great that it can auto-configure your location via location services, but it should degrade gracefully without access to location services and accept a manually-entered location and/or use your last known location.
carrythebanner about Mercury Weather, v2.6.0