I have a web-based mobile app which uses submit buttons styled with the following CSS class:
.submit_button_green input {
height: 26px;
width: 61px;
border: 0px solid;
font-size: 14px;
color: fff;
background-color: #00CC33;
font-weight: bold;
margin-top: -4px;
text-shadow: 0px 2px 2px #333;
text-align: center;
-webkit-appearance: none;
}
On iPhone 4 (iOS7) corners are still slightly rounded corners and button text is positioned to the right (disappears off the right side of the button). On android devices, button is perfect.