I made a simple ✦Neural Transfer app✦ (applies the style of one image to another) via Streamlit and deployed it on Heroku for free. You can upload your own images and the network will be trained in real time!
Since the server is free, there are some constraints. For example, I could not use VGG19-net because its weights are too large, so had to switch to Alexnet. That's why the performance may not be too impressive. It also runs slow, but does the job eventually.