MFSignatureKit gives you full signature functionality.
Installation is easy. Just drag and drop MFSignatureView.h and MFSignatureView.m into your project.
In your sub view:
#import "MFSignatureView.h"
To declare a new instance of MFSignatureView:
MFSignatureView *signatureView = [[MFSignatureView alloc] initWithFrame:self.view.frame];
signatureView.lineWidth = 10;
signatureView.lineColor = [UIColor blackColor];
signatureView.bgColor = [UIColor whiteColor];
[self.view addSubview:signatureView];
That's all there is to it! Now you can easily add a signature to your project.
In your own button, tap recognizer, or however you seem fit, add this code to clear the signature:
[signatureView setPath:nil];
[signatureView setNeedsDisplay];
And that's it, baby!