A React Native module which wraps ActionSheetIOS, CameraRoll and undocummented ImagePickerIOS to select a photo from the PhotoLibrary or CameraRoll. No external plugins needed.
npm install react-native-imagepicker- You need to include the 
RCTCameraRoll.xcodeproj(react-native/Libraries/CameraRoll/RCTCameraRoll.xcodeproj) in your project Libraries, and then make sure libRCTCameraRoll.a is included under "Link Binary With Libraries" in the Build Phases tab. Get more info on official site: Linking Libraries. Steps are very similar. - IMPORTANT: some versions before v0.17 have 2 bugs (#4411, #4412).
So you need to replace file 
react-native/Libraries/CameraRoll/RCTImagePickerManager.mwith this one or update to v0.17. 
Basics
var imagePicker = require('react-native-imagepicker');
imagePicker.open({
    takePhoto: true,
    useLastPhoto: true,
    chooseFromLibrary: true
}).then(function(imageUri) {
    console.log('imageUri', imageUri);
}, function() {
    console.log('user cancel');
});Each button (takePhoto, useLastPhoto, chooseFromLibrary) can be configure in following way
imagePicker.open({
    cancelTitle: 'Your custom title',
    takePhoto: {
        title: 'Your custom title',
        config: { /* Config object to ImagePickerIOS.openCameraDialog() */ }
    },
    useLastPhoto: {
        title: 'Your custom title',
        config: { /* Config object to CameraRoll.getPhotos() */ }
    },
    chooseFromLibrary: {
        title: 'Your custom title',
        config: { /* Config object to ImagePickerIOS.openSelectDialog() */ }
    },
    ...
})Also you can disable some of buttons
var imagePicker = require('react-native-imagepicker');
imagePicker.open({
    takePhoto: 'Custom title',  // Shorthand for custom title
    useLastPhoto: false, // disable this button
    chooseFromLibrary: true // get default values
})imageUri from Promise can be directly passed to <Image/> or FormData
...
render() {
    <Image source={uri: imageUri, isStatic: true}/>
} 
...var fd = new FormData();
fd.append('photo', {
    uri: imageUri,
    type: 'image/jpeg',
    name: 'photo.jpg'
});