You can use It is FREE. It runs under the browser of your choice.
If you own an I strongly recommend buying it: it is an app which sells for $2.99. It is much faster than computing on Wolfram's computer in Illinois and bringing the answer back to San Diego.

BEWARE the fancier "Wolfram|Alpha Pro" version since it costs money per month. I do not know the advantages over the $3 version, so I doubt they are worth it.


Alternatively use the web browser on your mobile device and go to the website "" to use the free "Wolfram|Alpha" web interface that has been re-organized for smaller phone screens instead of the regular "" website which assumes you're using a large-screen computer.