Hi Sorex,
yes I am probably going to rename it: "Gem Drop : Block Puzzle", as you say, gem tris is already taken, and not made of normal words, and block puzzle get's used by a lot of Tetris clones, which will help the ASO value of my game.
I'm hoping my game will stand out above the other clones, as I am putting a lot of work into adding "juice" to it, making it run very smooth, have nice graphical effects and feel like a polished game. The truth is, most single dev games on the app stores look very simple and no where near the level of professional games, this is why they get no downloads. But you spend the time (and some money on assets), then you can make your game stand out.