This app was mentioned in 7 comments, with an average of 7.29 upvotes
You can download a free, searchable, and annotated copy to your phone as well.
Edit: What I use. There may be better options out there. I found this one a few years ago and stuck with it.
I really do carry a copy with me everywhere I go.
Everyone should (serious).
https://play.google.com/store/apps/details?id=com.hotrod.reference.spiritofseventysix&hl=en
I'd prefer the ebook myself ..Or the app
Free Constitution app https://play.google.com/store/apps/details?id=com.hotrod.reference.spiritofseventysix
Contains the full text of the constitution, along with all the amendments, an appendix featuring a timeline, typos, and other fun facts, as well as the full texts of several other important American historical documents.
I find it comes in extremely handy when yet another self-proclaimed expert is spewing some BS about Americas origins and legal foundation.