Template Builder by StampReady Commented HTML. Flexible table structure (delete/copy/replace). Responsive for your mobile device. Compatible with FreshMail Test sending directly at the demo page. Conversion Centered Design Save your draft and edit later in Builder’s 2 Layout Style (Boxed and Full width). Advanced lossy compression for PNG,JPG (reduce png,jpg file size -70%) Compatible with awesome WordPress plunin MyMail Compatible with StampReady an Export file usable with MailChimp. 18 Repeatable modules for main template.
Modular style template easy to realign edit content customize color or even sending your campaign directly from the builder.
Gmail app is not support responsive yet according to this info and this and more info, and here about app, device that support responsive email
Not support Gmail App on Android. Please view in native email app instead.