I just tried it and if looks cool
The only small improvement it could see is a monospace font. In my opinion that's a must for all clocks, but even the Offscreen-app you linked to does not use it.
Too bad I don't really play go often, I would use this clock just for fun's sake.
By the way, I got exactly the same phone as you! Sucks to be a non-iphone/-android user these days, doesn't it? I'm thinking about selling this one, putting some cash on top and getting one of the cheaper android phones. Problem is, those phone have a worse screen (especially the resolution) - and paying just to use a 320x240 screen is just not my thing, even if I get android and wifi. (also, due to the low screen resolution, many android apps will not even work on those phones...)
edit: I just tried it again and found a rather important bug: The clock is not accurate, it runs slower than a correct clock. The difference gets bigger with time, so I suspect you have to change a few lines in the main loop that checks if the screen is touched.