Joint Number Place comes from Yuki Fujimoto. The object is to form a Latin Square such that: each row and column has numbers 1-n. Also, each colored area has numbers 1-n. 

Each black line connects consecutive numbers x and x + 1. Kropk'i Sudoku (see link below) had a similar feature.
  There are 25 levels in each grid size from 4x4 through 9x9.

These puzzles are fun and challenging.  I've solved all the 4x4's, half the 5x5's and some 6x6's.  I tried the 9x9's: no progress - yet.
The graphics for Joint Number Place are overdone. There should be no white or tan squares.  The background should be black.  The connecting lines should not have two colors. These are minor complaints.

https://itunes.apple.com/us/app/joint-number-place/id1312632074"mt=8

Other Latin Square Puzzles
Sudoku Sweeper
Futoshiki  also known as Hi-Lo Sudoku
LogicCity
Kropk'i Sudoku
Logi5Puzz
TetragonoS

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