Orbitel is the international arm of the Colombian UNE EPM. Mainly focused on the Latin American market Orbitel does offer very competitive long distance rates. However being that these are in the form of a pre-paid calling card; these have the drawbacks usually experienced with calling cards. Namely, if you have to use a 1-800 number you'll pay extra, and the top-up would expire either at 60-days for calling cards or one year using the rechargeable option.
In our Orbitel review, we did find it to have good rates when compared to others, but the time restrictions put them a slot down from the Long Distance providers.
There is also an App for Android and one may be coming for iPhone but it appears to be only on the Spanish site.
In all, if you'll be making a lot of calling to Latin America then Orbitel is a very good option to consider. But, keep in mind you'll have to use Orbitel Local Access Numbers and the top-up have expiration dates. We prefer to have no expiration date, as far as we are aware the Canadian dollar doesn't have an expiration date.