Drop7 is my current favorite game.
I used to get on the leaderboard with it every day.
It's best on the iPad, because of the bigger screen, but I recently sold my iPad to pay for my acting classes. Days later, through sheer coincidence, my iPhone died on me out of the blue. Then I made and sold a time management video, and made enough money to buy a new iPad and/or iPhone, but I decided not to, because I had already started coding a clone of Drop7, and I suspected that if I bought a machine that ran the real Drop7, I wouldn't finish my clone.
Unfortunately, I soon discovered Chain Factor, the original Flash version which Drop7 started life as. For days after I discovered Chain Factor, I didn't do any work on my Ruby clone.
I can't say I was surprised.
I got on the leaderboard immediately, and at one point, two of the top ten scores for basic mode daily were both mine. So, with my code-inspiring Drop7 starvation ended, I'm probably just going to make another video and buy a new iPad. Alternatively, I may put Chain Factor on a hosts-file ban and stick with it. Either way, I've open-sourced my Ruby clone, and any further dev I do on that will happen in public on GitHub.
Here's my command-line clone.
As you can see the command-line version lacks the special effects of the iOS version. No shock there, I hope. I've also created a very basic Web UI:
As much fun as I've had with this thing, I'm going to recommend that you just buy Drop7. However, if you want to play with this, the code is on GitHub.