Looking for an app thst let’s me add text boxes (not just annotation comments) and singing to a PDF.
Most of what I’ve found only does annotations.
I have obtanium so its ok if not hosted directly on f-droid.
FWIW I use xournal to sign pdfs with an image of my signature. Not exactly a form though.
The thing that you’re looking for is called “PDF forms”.
I can’t find an app by this name. What repository is it in?
It’s not an app, the technology you described is called a “PDF form”.
So it’s not the thing they were looking for
It appears that the OP is incapable of discovering Adobe Acrobat.
I spent the day looking for a desktop app that does this and finally found Scribus. The fact that most desktop Linux PDF readers and editors cannot do this satisfactorily does not make me hopeful that such an app exists for Android.