The feature is automatically disabled in the app on an iPhone4, and will automatically be made available once the device is loaded with the firmware to support it - V3.2 and up. Connects to your WatchMate device's WIFI access point or by being on the same wifi network. - Supports Vesper Marine XB-8000 AIS Transponder. - Supports Vesper Marine WatchMate Vision®. The complex nature of our innovative WatchMate App makes coding mishaps difficult to eliminate despite the superhuman efforts of our developers so please remember Vesper Marine does not warrant that this product is error-free. As the adventurous user it's your job to exercise common sense and the best navigational judgement you can muster. Although we think the WatchMate App is awesome nothing beats using all your human senses, so best you still rely on these at least as much as you rely on the WatchMate App for making navigational safety decisions. Our advice is; even with the WatchMate App it’s still a clever idea to maintain a permanent watch and use more than one aid for navigation.