It was only a matter of time before the over-the-top messaging apps got tired of upturning the mobile carriers’ SMS businesses and developed ambitions of becoming carriers themselves. WhatsApp is getting its own prepaid SIM card on Germany’s E-Plus, which combines unlimited WhatsApp usage with a small bundle of traditional mobile voice, data and text messages for €10 ($13.80).

WhatsApp CEO and co-founder Jan Koum announced the partnership at Mobile World Congress in February, but TechCrunch and German media spotted the launch of the service on E-Plus’s website on Monday. The deal isn’t your typical mobile virtual network operator deal because WhatsApp isn’t supplanting E-Plus’s brand and selling voice and data directly to consumers. But the partnership is unique in that the prepaid service seems to focus on WhatsApp as the primary mode of communication. As WhatsApp rolls out its planned voice services this quarter, that focus could become even…