There is no specific smartphone/iPod/iPad app for LXBeams. However, LXBeams has a built-in web server that means that you can use your smartphone/iPod/iPad's web browser to view your plot and report windows.
To do this choose File->Export->Share on Network.
You will get an alert telling you sharing is started at an address like 12.34.56.78:9101.
(You will need to either disable your firewall or allow an external connection to LXBeams. The firewall is found in the Mac's System Preferences' Security pane.)
Type the address (eg. 12.34.56.78:9101) into the browser on your smartphone/iPod/iPad. You will get a web page that lists links to the open windows in LXBeams. Clicking on a link to a plot window will show a PDF of the plot. Report windows have a plain HTML and Javascript version. The Javascript version allows you to edit information and send it to LXBeams.
There are several preference options (in the Export pane) that are associated with net sharing. One is the network interface to use. This allows you to select between an Airport or Ethernet connection to use for net sharing. You can set a specific port number to use. This is the number after the colon in the web address (9101 in the above example). This can be useful if you need to setup a firewall to allow a connection. The cache manifest option tells your mobile device to cache the data it receives. This means that you can view it, later, even without an internet connection, if you don't close the browser window. Finally, the allow post/put connections is necessary to modify your plot's data from a web page.
If you are using an iPhone, your best bet on the network connection is to have your iPhone and Mac both connected to the same wireless connection. If the Mac is connected to a wireless connection and the iPhone connected to a cellular connection, the wireless router likely has a firewall that would need the port assigned to LXBeams's server opened up. However, you would need to be able to (and know how to) administer the wireless router to do this.