hellooo um um before the actual review, there are a lot of grammar errors in your app. and since you keep repeating them, i'm guessing they were not by accident. i'm not saying this in any sort of insulting way, i'm just trying to help you make your app better C: I would suggest
http://www.reverso.net/spell-checker/english-spelling-grammar/ this site. it will help a bit (probably). as for the whole there/they're/their deal, i'll just write this down for you since it's quick and easy.
where? there.
they're = they are (the a is just cut off)
their = possession (their house is big (they have a big house))
now that that's done, let's move on to the more juicy stuff ehem ehem
one; personality. first off, this needs to be at least 200 words long. second, i can't see how he could be a shy, closed off type of guy, but also be trusting and enjoy making friends. a shy, closed off type of guy is the guy who sits by himself and avoids any sort of interaction with others. maybe you meant quiet guy? like, someone who has friends, likes making friends, but isn't exactly the party animal of the group? also, to lengthen the personality easier, try and add how reactions to certain situations (when his friends get hurt, when he himself gets hurt, how open he is when it comes to personal stuff, etc).
two; physical traits is a title, no need for a description next to it. that should go into appearance.
three; put none in rank instead of dots since you put that in special title section too lol (not mandatory, but to keep things neat)
four; appearance. again, you fell sort of words, this needs to be 100 words long. also, your character's weight and height set doesn't add up with the description of being skinny. according to the numbers he's actually somewhat chubby if not a normal healthy weight. also, jeans don't really exist in the aot universe(??), at least not yet. to pull up the word count, try and describe his face characteristics and his frame.
five; likes and dislikes must each be 50 words long. this means you need to add a small description to at least one of the likes (and one of the dislikes). for example, why does he like strategy? how did he come to know it? or, why does he dislike asthma? (i know this is obvious, but that's what i'm trying to say. you can write a small description for at least one, especially if it's this obvious, should be easier). also, i think geography isn't really a thing? i mean, books about the outside world are practically banned, so, it's difficult to study on it. so, um, idk, explain, i guess(???)
six; again, fears and motivations should be 50 words each. describe the reason behind a fear and a motivation maybe? to get up the word count and stuff.
seven; background. so, ah, as a general idea, it's good. but there's a lot that doesn't really add up. one is that if a 5 year old and new born baby were left with no parents due to government oriented reasons, they would be put in an orphanage most likely, if not sent off to live with another relative. besides, if you give a 5 year old a baby and tell them to survive, they will cry and most likely die very soon. two, it's called colossal titan, and i doubt their father would be eaten in front of them. during the breach, everything was hectic af, people were running, and two (practically) orphan children could not have ended up with their father at the exact right moment when he would be eaten by a titan. unless he was visiting them/seeing them for whatever reason and decided to disobey orders and stay with them instead when he was asked to go up front and serve as a soldier like he's supposed to do as soon as word of the titans broke, they wouldn't be anywhere near each other. the moving into wall rose part is very good and all, but please fix the rest. also backstory needs to be at least 350 words long. try and go into more detail of their early lives maybe? how warren ended up studying whatever he's studying and where he found the means to study? did he find a donor? a teacher? is he stealing books from libraries? (idek--)
eight; oh one last thing i forgot. he's quite young to be a bartender, but i can skip that because, well, the situation allows for young people to get whatever job is available. but i can't really see how he would be a bartender with that shy personality of his? wouldn't the customers end up feeling awkward around him? or he awkward around them?
when you're done editing, just pm me <3