Questions

Page repairs, answered

Does rotating stay after I send the file?: Yes. The rotation is stored in the document, not in your viewer.
Is the original changed?: No. You get a new file and keep the one you started with.
Can it straighten a crooked scan?: No. Rotation works in quarter turns; a few degrees of skew is a different problem.
Is anything uploaded?: No — these tools run in your browser.
What does a subscription change?: The download. Everything up to it is open.
Whose page is this?: It is run by the team behind PDFora.