There are several ways to do that. REST web service, URL shortening, changing the alias or creating an .htacces file.
An easy way to do that would be creating an .htaccess file in your root directory.
If you’re running Apache, you can do that by creating a redirect in your site’s .htaccess file. If you don’t already have one, just create a new file called “.htaccess” in your site’s web root.
Save this inside your .htaccess file:
<IfModule mod_rewrite.c>
RewriteEngine On
# Send would-be 404 requests to Craft
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php?/$1 [L]
</IfModule>
That rewrite rule basically says, “If a request is coming in that doesn’t map to an existing folder or file, pass it along to index.php instead.”
source http://buildwithcraft.com/help/remove-index.php
and check this htaccess remove index.php from url