Fives is a mobile game that's all about combining like numbers. Numbers are arranged on a 4x4 grid, and your score is determined by how many you can combine before you have no more moves left. Here is an example of what the board might look like at the end of a game:
That might look a little confusing until you understand what you do in the game. On each turn you can slide the board up, down, left, or right. Every number on the board will move in that direction if it can (they will not slide off the end of the board). Twos will combine with threes to make fives, and every number after that will combine with like numbers (fives with fives, tens with tens, etc). When numbers combine the new number is the addition of the two old numbers. Also when you make your move a new number will slide in on the side of the board you are pulling from. So if you slide everything down, a new number will appear in one of the slots at the top of the board. As you can see above, there were no more moves I could make because there were no numbers adjacent to numbers they could combine with.
The board starts out will all twos and threes, and your score is determined by how many moves you made and how large the numbers are on the board by the end. It is a very good idea to pay attention to what the next number is, so that you can pull in a direction that will place it near other numbers like it. Otherwise the board fills up very quickly. Take the below screenshot as an example: Although pulling left here only allows me to combine one pair of numbers, they are the largest numbers on the board, and on the next turn I will be able to pull down and combine three numbers at once. Furthermore, I know that the next number is a twenty, so I am positioning it near several tens that will soon become twenties.
Fives has several monetization models; you can play the game for free with ads. These ads show up in a small banner below the next number indicator, and a large ad pops up after each game. You can get rid of these ads by paying $2, which I did. You also have a limited number of undos and chances to change the next number. You can earn these by scoring over 10,000 points (which takes a long time) or you can buy them for $1 a piece. This is not worth it in my mind, and I am sure that some of the global high scores exist because people spent a lot more money than they should have in order to get up there. Fives appears to only be available on Android.
I've enjoyed playing Fives but other than +Ryan Rampersad I don't know anyone who plays it, and he will never get anywhere near my high score. Much like Dots, I think I am done with this game.
Update: Fives is most certainly a clone of Threes! which is now available on Android, so I recommend checking that out instead.