Rocket Power Up

So what's a rocket power up? You'll get a rocket if you match 4 pieces in an adjacent tile. You will get a yellow and purple piece that has pointed ends appearing on your game. These are Rocket power ups which clear the entire row it's pointing to. You can activate this by swapping them with any adjacent tile, therefore you can clear the row that has most of the pieces that you need.

An alternative method, if you don't need to move your rocket, is by simply double tapping it. It will clear the row it's pointing at immediately. If you're able to do 3 piece adjacent swaps and filling an entire row of the pieces you need, you can then use the rocket after to clear that row.