Apps that run directly on the SIM card are relatively unknown in the US. We (in Canada) normally download apps that run on the phone's OS, like Android or iOS apps. Running apps directly on the SIM card is very unlikely.
I played around with a TurboSim for a while too back when I was testing out a SIM card 'firewall' that would block the carrier programmed SIM from responding to OTA updates or type-0 stealth SMS and other bad things http://www.bladox.com/ then phones with wifi that didn't require a SIM came out.
