I went to an interview prep workshop where they breezed through some common errors in the app for Delta and United and there were quite a few people in the crowd who were making corrections. I originally filled out my app when I wasn't competitive and slowly honed it to what they wanted. Delta is slightly different from United but has similar kisses of death like expired medicals, passports, and poor grammar. If you accidentally check a box and they think you inflated your app unethically you are potentially kissing a fantastic job goodbye forever.

You don't need to pay for a good app review but go through it with a fine tooth comb and click on the help/? that explains what they are asking. After you go through it let a buddy with better grammar and spelling look it over. Go through it every few months and try and fine tune a few sections.