Want that long exposure look for waterfalls, creeks or fountains photos and don’t have a DSLR? Then just use your iPhone. You need to be up to ios11 on your iPhone. In the camera app, choose the Photo function (not portrait, square, video, etc) and then click on the Live Photo button (the three ring option on the menu on the other side of the screen should be next to the flash icon). Frame the image a little bigger than you want in the end, as it will crop it a little. Hold the camera still for a little bit before and after you take the photo.
To put the long exposure on, when you open the photo in the photo app swipe up and you will have a couple of effects to choose from – choose Long exposure over to the right. Note if you have a Live Photo already then you can apply the long exposure after the fact too.
Unfortunately, the live photo option is only available on an iPhone 6s or newer.