Scan each document so it is clear and readable; don't encrypt or password-protect the file.
Each file can be up to 12 MB; the app keeps it under that.
Documents in another language need a certified English translation.
How to do it with Requisito Listo
Open «USCIS online filing: evidence».
Scan the pages with the camera or pick a PDF or photos you already have.
Put the pages in order.
The app builds the PDF under the size the portal asks for.
At the end you'll see a checklist: size, file weight, background and format. If something doesn't comply, it tells you what to fix before the portal rejects it.