iOS and Android devices kind of compliment each other in this matter.
On one hand Apple restricts the use of BlueTooth, which makes it impossible to receive NMEA data over a Bluetooth connection. But if you have a device that establishes a WiFi network, you can make an Ad Hoc connection and get your data using the TCP or UDP protocol.
On the other hand Android doesn't support WiFi Ad Hoc connections (not before Android 4.0), meaning that almost none of the existing Android devices will be able to make that kind of connection. But Bluetooth is unrestricted, so the "easy" way to get instrument data into your Android device is over Bluetooth.
iRegatta for iOS does support WiFi connection and both TCP and UDP protocols for getting NMEA data.
iRegatta for Android will pretty soon support Bluetooth connection for NMEA data input. First tests have been made, and the free app "iNmeaLogger" has been published. This can be used to test if a connection can be made between the Android device and the NMEA bluetooth device, and if data are transmitted.