You can build and use SFML for Android as well as iOS. Support for both systems is still experimental and incomplete (read: Stuff might break, code might change, things might be incomplete).
There are a few games on Google Play made with SFML. You can create and publish games or apps with it, just keep in mind there might be incompatibilities and many things might lack testing.
iOS isn't dropped nor really frozen, it's just lacking people working on it, due to the requirements to actually write, debug, and test code (you a Mac, and a developer license, ideally an actual iOS device as well).
