This app is called Legend. This app is amazing. If you do not already have this app dowloaded i suggest you do so. This app puts text over any picture you want and you can type in whatever you want. You can then put different effects for the writing e.g. it having quotation marks around the words, making the text blink etc.
This is what I have made on Legend so far. Yes i had to make a Legend one because of the app name and I love the Legend. I love this app even though I've only had it for about 10 minutes.