Weekly top iPad apps: games that will make you think

This week's selection of iPad apps include games that will test your mental and vocabulary skills.

Sudoku 2 HD Pro
Sudoku 2 HD Pro is a number placement puzzle. Users try to place digits from 1 to 9 in a grid so that no row or column shares the same number. Users are calling Sudoku 2 HD Pro the "best sudoku on the iPad," praising the game's slick HD graphics, intuitive user interface, and great features. Sudoku 2 HD includes a point-scoring system, online leader boards, and five different levels of game play.
Price: $2.99

The traditional family letter game, Scrabble, has been revamped for its iPad release. Scrabble for iPad lets you compete against the computer, battle against other players across the world in an online game or invite your friends over and have a real digital game of Scrabble with up to four players. Players can download the free Scrabble Tile Rack Application on their iPhone or iPod touch to keep their tiles hidden from the other players when in Party Play mode.
Price: $9.99

Cogs HD
Cogs HD is a game for creative puzzle solvers who like to think in three dimensions. Players must slide tiles with gears, pipes, balloons and chimes on them into place in both 2D and 3D environments. Each correct tile placement brings players closer to making their complex machine work and closer to the next level.
Price: $4.99

Boggle for iPad
The original Boggle wordsearch game has been digitized for the iPad. Users search through jumbled up letters to create as many words as possible before the clock runs out. Players can challenge their friends or collect achievements as they improve their own word skills.
Price: $1.99

Crosswords presents players with a selection of daily crossword word puzzles from top newspapers around the world. Each crossword comes with hints, clue look-ups and detailed information. Players can also compare their solve times with those of other players.
Price: $9.99