Mobile UI Design & Development Guide
Best Practices

Most of the existing PowerBuilder controls can be used and deployed to the mobile device, except for RichTextEdit, Animation, InkEdit, InkPicture, and OLE. You can use the PowerBuilder controls in the mobile application, just like how you use them in the PowerBuilder application, but keep in mind to set proper size for them and leave spacing between them. Apple recommends the target area to be average finger-tip size which is 44*44 points (approximately 176 * 176 PBUs). This is the ideal size we should strive for, but definitely this is no iron rule. You may find other practical rules for the real situations, such as set the control size to 44 points high or wide and reduce the other dimension to no smaller than 30 points (approximately 87 PBUs) if space is really limited, or leave space or padding between controls to make the target area closed to this size.