Owtel is a Long Distance provider, with HQ in Hong Kong and offices in Markham, ON. The target market of Owtel is the Filipino community, offering decent long distance rates. It works as a traditional Phone Card service, but it doesn't have the additional fees for a phone card. So you'll need to dial a local access number or a toll-free number.
Owtel also offers a referral program in where users can refer other potential customers, in which case upon a successful referral will get a discount. This is similar to other programs with Long Distance providers; though Owtel is known for calling their users and asking them for referrals, whereas other providers have a less aggressive/invasive approach.
In our Owtel Review, we found the international long distance rates are in some cases twice as much as our Top Long Distance Providers. For example, Canada wide rate is $0.03, when typically we have seen it at $0.01. Though this is slightly confusing. That is because if you use the Owtel App, calls and Text Messages to the US & Canada are free of charge. The App is available for Android and iOS.
Thus in summary Owtel could be an option, if you are comfortable using apps. But you'll have to think it twice in case you want to get flooded with telemarketing calls from them.