The Signeasy app supports document sizes up to 40 MB. 

Just a couple of things to keep in mind when in regards to document size:

• Most email providers limit attachment size to 25 MB. Attaching documents won't be possible if the size is larger than 25 MB.
• Larger document sizes may take longer to synchronize across your devices or save as drafts.
• Be careful adding images, as they can quickly add to your document size.