I think the app can make a different, but not always. I used to have like 5 different camera apps because each did something a little different. Ultimately, it’s you and the phone that matter. Some phones will take shitty photos no matter what you do. Some people take shitty photos no matter what they do. The more you know how your gear works and where it falls short and where it excels, the better your photos will be. And do some post processing: never accept something without giving it some polish.