Platforms: iOS, Windows 8 (both free)
Adobe’s e-signature app lets you sign documents, send documents for signatures, get documents signed in person, or sign documents for other EchoSign users. Upload documents from your SkyDrive, Dropbox, Google Drive, or Box account. You can also upload photos from your tablet (for example, if you happened to take a photo of the document that needs to be signed). The first five contracts you sign per month on EchoSign are free. After that, you’ll need a subscription (between $14.95/month and $399/month).