Tango Unlimited is an independent, free take on the sun-and-moon puzzle that LinkedIn's Tango made popular, with no ties to LinkedIn. You fill a 6×6 grid so each row and column holds three suns and three moons, no symbol appears three times running in a line, and cells linked by = must match while × means they differ. Each board has a single solution reachable by logic. Beyond the numbered daily, there are unlimited boards in three difficulties and an archive. A grid that resolves one forced cell at a time is deeply satisfying.
Small grids solved by deduction fill the list. Binary grids with the same balance rules come first, then puzzle hubs that host Tango-style boards, then grids with marks between neighboring cells, and finally other short daily logic puzzles of the kind that sit beside Tango, from star placement to paths, dominoes and rectangles.
The nearest relative: light and dark squares stand in for suns and moons, each line is split evenly, runs of three identical neighbors are ruled out, and tie and cross marks between cells do the job of Tango's = and ×.
Puts a suns-and-moons grid among thirteen daily puzzles, next to crown placement in colored regions, mini sudoku, word ladders and searches for hidden words, enough for a long session after the daily Tango.
Shares Tango's habit of marking how neighbors relate: dots placed between cells show when two digits are one apart or when one is twice the other, on sudoku boards in a range of sizes and difficulties.
Another 6x6 grid with balance rules: six stars must be spread so that each row, column and colored area holds one apiece, with none touching, not even corner to corner.
Uses the same 6x6 footprint for digits: each of 1 to 6 appears once in every row, column and small box, and its hints explain the logic behind a move, much as Tango Unlimited's hints name the rule that forces a cell.
Inkwell Games' star puzzle: shaded regions each need a set count of stars, as do the rows and columns, and stars can never be neighbors, so it trades suns and moons for a placement count.
Conceals enemies on a sonar map, exactly one in each line and sector and never adjacent, across boards that grow from 6x6 to 9x9, the same count-per-line discipline Tango demands with a different symbol.
Divides a grid into rectangles, each containing a single number that matches its size, on 5x5, 7x7 and 9x9 boards, with hints that explain their reasoning, close to Tango Unlimited's teaching approach.
Fills a grid with digits so that every stretch between blue dividers, in either direction, uses each number from 1 up to its length once, the same line-by-line balancing as suns and moons.
Solves nonograms from the clue numbers on rows and columns, on boards of 6x6 up to 12x12, and finishing a line wrongly costs a ten-second penalty, a timed counterpart to the clock on Tango boards.
It uses the same rules, three suns and three moons in every line, never three of one symbol side by side, and = and × signs between cells, but it is an independent site with no link to LinkedIn. It adds unlimited boards in three difficulties, an archive of earlier days, and an iPhone app with streaks, leaderboards and offline play.
Pressing Hint fills a cell and tells you which rule forced it, working through the = and × signs first, then the ban on three in a row, then the tally of each symbol per line. A setting can also show your mistakes as you go, and each archived day lists how many steps of each kind its board needed.
Twill uses the same rules with light and dark squares and tie and cross marks. Coronet Arcade hosts Tango-style grids among many daily puzzles. IQiQGame Kropki Sudoku carries a similar idea into numbers, with dots that describe how two neighboring cells relate.
