Search Engines. Add your site to all major search engines like Google search, Yahoo and Bing. This is the best way of getting free traffic.

Title / Meta Tag Give each page a title that best describes the content of the page.
Add meta tags and descriptions in all pages.
This will increase your site's visibility in search engines.

Link Exchange. Exchange link with other sites that provide same service as yours.

Toplist / Directory Add your site to good toplist / mobile directories, this is the easiest way of getting traffic to your site.

NB: Adding fake links which redirect to toplists may get your visitors irritated and they may never return to your site.

Guestbook / Forum Always post a link to your site in any guestbook or forum you come across, the simple truth is that the site owner may delete your post but keep on posting.

Mobile Advertising Advertising your site is also a very good and quick means of increasing your traffic.
Recommend Ad. Network: buzzcity.com
This method requires money.

NB: This method may be wasting of money if you have little or no quality content in your site, because visitors will always hit their back button if they couldn't found what they want in your site.