Mobile payments represent a new concept, which is rapidly gaining importance within payment processing industry. Payment applications, installed on mobile devices open new horizons for mobile payment processing.
There are several mobile payment solutions you can choose from in order to find the most suitable answer for your particular situation.
The easiest option is to resort to the so-called in-app payment solution. In this case mobile payments will be processed through API, provided by the online store itself. Another option is to use the payment page, located on the server of the payment service provider. In these two cases PCI exposure level is reduced to zero. Still another option is integration of your payment application with the external API of the PSP. There are several ways to implement such integration, but in any case it is better to consult QSA regarding PCI audit.
More information on mobile and tablet payments, as well as on mobile credit card processing can be found in the respective article on Paylosophy.