Who's here? Who's around?

之前提過個點子，果真有人寫出這樣的軟體來～

看這裡

http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=284973016&mt=8

http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=307838489&mt=8