If viewing the blog with a mobile browser you can not see the banner at the top of the full web page browser where you can put in your email in to subscribe to my blog postings.
To get around being able to subscribe usually mobile browser defaults have near the bottom of the web page a link to the full browser view. Click this and go to the top left of the page and you will see a bar to put your email address in. You only have to do this once.
The other alternative is to view the blog on a laptop or desktop.