This pilot uses it right now; well, technically I use an app called ForeFlight that's a bit more mature than the app in the OP however it's the same exact concept.<p>It's wonderful; I still keep paper charts as backups but never use them anymore. ForeFlight just released a new version that meshes GPS data with the instrument procedure maps (called approach plates) as well as with airport maps (really really handy when you've landed at an airport with a ton of taxiways).<p>They even built in a way to further dim the iPad screen so you don't blow out your eyes at night.<p>The GPS antenna in the iPad is a bit weak, but there's a slick BlueTooth enabled widget that takes care of that issue.<p>The only downside is that there's no datalink, which means no live weather. As the OP mentions, once can download weather ahead of time but that's only sufficient for pre-flight planning. On a long cross country over varied terrain in instrument meteorological conditions (IMC) it's still handy to have at least a Garmin handheld device with XM Weather. There are still flight service stations (FSS) that can help you out with the weather but there's nothing like pulling up Nexrad data to your cockpit display while in the soup.