I just found this app and started fiddling with it. These are results from my own photos with no tweaking.
There are dozens of 'apply a filter to photo' apps out there and this is totally different.
Photoshop has had 'artistic' filters for ages, but you always had to apply them yourself very carefully.
This app does all the tweaking automagically and transforms an input photo into each possible style with zero fiddling. Then you get a single one-dimensional option to alpha blend your original with the 'artified' one, and that's it.
I went to the website to see if it was available for Android, and saw it is called Prisma AI, after I had already guessed that they were using machine learning to set the parameters for each photo.
Downsides: hard-coded square crop, as far as I can tell, and hard-coded low-res limit (~ 1 Megapixel), and the worst part (which also gives away that this is some heavy duty AI stuff): it only runs on their servers, so you can get stuck in the queue and it only works with a network connection. Also, they apply a watermark in the corner.
If I had to guess what their business model is, since the app is free with no in-app purchase (they may add in-app purchase to make it work off-line, possibly -- then it would be a pro tool instead of a toy) their entire business model is venture-backed and they are going for an "Instagram has no choice but to buy us" approach.
But technically and artistically this is seriously cool and worth fiddling with for a few minutes.
UPDATE: You can now turn off the watermark when you save images back to your camera roll.
UPDATE: About half of the filters now work off-line and you get results very quickly. Nice work.
UPDATE: They also support non-square aspect ratio now, too.