TensorFlow with Phonegap
TensorFlow is a tool to write computation using data flow graphs; this being said, if you want your app to use a pre-trained model only, there is no requirements to use TensorFlow specifically. You could even use one of the ML library written in Javascript to import and run the pre-trained model.


Javascript DL libs: http://cs.stanford.edu/people/karpathy/convnetjs/, https://github.com/dmlc/mxnet.js/
TensorFlow for mobile: https://www.tensorflow.org/mobile/
Caffe Android: https://github.com/sh1r0/caffe-android-lib
DL4J Android: https://deeplearning4j.org/android