PDFfiller!

This software overall is really well done. I prefer to use it when compared to other PDF filling software. It is also free, which is even better.

Pros

This software does all the hard work for you. It recognizes each possible area for text, and understand if there is an area for a diagram/picture/drawing instead. This software gives you multiple different ways to input your signature as well, which is always something I look for when it comes to similar software. Grammarly also works moderately well with this software, if that is something you use.

Cons

PDFfiller looks very busy. Even though it is relatively easy to use, it can seem daunting when you first start using this software.