Not mom related, well I guess kind of lol

So I love taking picture of my kids. I’m wondering.... is there an app that lets you change the background. Example: let’s say I take a picture with my kid outside and the background is ugly . Is there an app I can use to change the background completely? Not blur it out, I mean like change the background to something pretty like a field of flowers or dinosaurs 🦕 you know something like that.?