Increase Your Text Size Widget

Login into your Blogger.com

GO to Layout > Add a Gadget > Html/Javascript

Paste the below code and Save it -

<a href="javascript:void(0);" onclick="javascript:body.style.fontSize='.5em'"><span >+</span></a>
<a href="javascript:void(0);" onclick="javascript:body.style.fontSize='1em'"><span style="font-size: x-small;">+</span></a>
<a href="javascript:void(0);" onclick="javascript:body.style.fontSize='1.5em'"><span >+</span></a>
<a href="javascript:void(0);" onclick="javascript:body.style.fontSize='2em'"><span style="font-size: large;">+</span></a>
<a href="javascript:void(0);" onclick="javascript:body.style.fontSize='2.5em'"><span >+</span></a>


You can see the Demo Widget here in the Right Top of the Sidebar.