The reason for having two sim cards is different for every one. For me, I have a German and a Chinese sim card, one I use in Germany, the other one in China. If you know how much roaming O2 wants to have for texting or calling in China, you’d probably have two sim cards, too. Did I mention that it is cheaper to sent a SMS from China to Germany than from Germany to Germany?
So when using two sim cards with a dual-sim-adapter on an android phone, you never know which sim is currently active, which is quite irritating, so I developed MultiSim to solve this problem. MultiSim tracks all sim cards used with your phone. It can display a customizable icon of the current sim card on your notification bar if desired. You can list all sim cards MultiSim has detected in your phone and delete unused entries.
MultiSim also comes with the widget which allows quick one-click switching for dual-sim-adapter users. It dials the shortcut numbers and switches the flight-mode on and off while keeping any WiFi or Bluetooth connections alive. On rooted devices, a restart is also possible.
MultiSim can be downloaded from the Market. Simply search for “MultiSim” or scan the QR-Code.