Standard set: Heroku, AWS (1 year free), Bluemix, GAE, Pytho...
In terms of storing images:
- AWS for those that it is possible to store images directly in the V-world. Pour on dev - or using a bot, or via FTP.
- In other cases when PaaS you can store the picture in the form of binaries in a DB. If the service does not provide database or its size is small, it is possible to use mLab or MongoDB Atlas. There is a free 512 MB in the database.
- If you need, well, a lot (gigabytes) of images to store, can be stored on a normal free hosting of statics, to take from cloud storage (Yandex, Dropbox) or even organize a collection from some of the mail.