This is probably my most used app! I used for school all the time, had a ton of PDFs to read for classes. Now I use it for work constantly. I mainly use it to organize my documents (love that folders can have subfolders!) and to make notes, hi light etc. Have also used it so e-sign things and has worked great. Only filled out one form with it and it wasnt too bad but did take a bit longer than I think it should have.
TooManyCreditsToCount about TinyPDF - Fill Forms, Annotate PDF with Professional Reader, v3.0.1