You can create HTML iPhone signatures easily via CoolGeex.com an application developed to generate HTML iPhone signatures. here the signature can be directly create from your iPhone or from your computer or laptop.
After click on this link iPhone Signature Creator version 4 you will redirected to a page where you need to sign up for a account as usual on other site, you can also choose sign in with Facebook for easy sign in process. After sign up process you get a form to fill up the required details.
After that you got a notification on the top of the page that signature email sent successfully.
Now you need to check your email in your iPhone / iPad. There you received a link to a page of signature after selecting it you redirect to a Coolgeex Page just bookmark this page to your home screen & whenever you need to send email click on this bookmark on your home screen to get cool HTML signature.
How's this trick just let us know by your comments below. If you feel difficulty in making the signature then ask us for help.