Any good photo apps which have strong effects?

Whenever i take a pic, it is with a bad quality, i have iphone 5s! How do i improve my photos? And even if i use effect it makes the picture uglier… What's wrong?

Instagram. I hear it has new face filters.

No effect can improve the quality of a photograph. You are going to need to improve your picture making ability.

Those who say that you need to learn about photography are spot on.
It's not what you're using, it's how you are using it that's the problem. Every camera ever made has certain capabilities and compromises. Even the best pro Hasselblad has compromises where it's not really the "best" camera in some situations or for certain needs. So if someone was to invest $45,000 into a Hasselblad body and say another $4,000 into a great lens, and then try to shoot subjects for which the camera was not designed (e.g. Sports or fast action), the pictures aren't going to be anywhere as good as a camera system costing a fraction of the price. My point here is that the $15 camera in your $500 phone can be used to make great photos under specific situations. Trying to use it outside of the narrow set of situations will yield unacceptable images.

So with this in mind, you first need to understand the limitations of the camera within your phone. If those limitations are preventing you from getting the kinds of shots that you want, and the quality that you want, then it's time to get something else.

The camera in your phone is intended for daylight conditions or subjects that are close enough to be properly illuminated by its LED. So to get acceptable shots, you first need to be in areas that are well lit. Your next challenge is the camera's wide-angle lens. This lens is intended for group shots, landscapes, interior shots and the like. It was never designed to take a decent portrait because of the significant amount of wide-angle distortion inherent in the lens.

So what I'd like for you to take away from this response is that you can technically get very good results with your smartphone, providing that you are working within the parameters of the camera. No amount of filters or "edits" will help. Filters and edits should be used to enhance the qualities of the image as taken, not to somehow improve on something that's not in the shot in the first place. Remember, 80% of what makes a photo great happens outside of the camera. Your decisions regarding lighting, composition, subject matter and timing are THE MOST critical aspects of taking a great photo.

Before you start messing with effects, you need to get the actual art of photography down really well--composition, focus, lighting, etc. Even on a phone that's important. Once you have really good photos, you can work on enhancing them with effects and filters. This is just an example. The top photo is the original, taken with my phone. It was good as it was. But because it was good, I was able to enhance it with effects (the bottom two).

EDIT: Unfortunately the preview here on Answers seems to have compressed it and it looks blurry now. Grr.

EDIT 2: Here are links to the photos on my Flickr.
Original:
Enhanced:
Black and White: