An alternative to Thermometers - Logic Puzzles.
Same puzzle, smaller library. Mercuro trades 9,000 boards for 660 curated ones, three dailies a day and prices you pay once.
Mercuro, the Thermometers puzzle for iPhone and iPad
Free to play. No subscription.
Mercuro and Thermometers - Logic Puzzles side by side
| Mercuro | Thermometers - Logic Puzzles | |
|---|---|---|
| Price | Free; $2.99 once to remove ads, or $4.99 once for Pro | Free; in-app purchases are a one-time $3.99 remove-ads pack, a $3.99 monthly membership and a $1.99 weekly membership (Thermometers - Logic Puzzles on the App Store) |
| Puzzles | 660 curated, 330 of them free, on 8 board sizes from 5x5 to 12x12 | 9,000+ from 4x4 to 17x17 (Thermometers - Logic Puzzles on the App Store) |
| Difficulty | Sorted by board size, with chapters that open as you solve | Five levels, Beginner to Master (Thermometers - Logic Puzzles on the App Store) |
| Daily play | Three new puzzles a day (Warm-Up, Daily and Challenge) | A daily challenge puzzle (Thermometers - Logic Puzzles on the App Store) |
| Runs on | iOS 17 or later | iOS 13 or later (Thermometers - Logic Puzzles on the App Store) |
Checked 2026-10-08 on the US App Store. Prices and features change, so see each app's own listing.
Three dailies, not one
Its daily challenge is one puzzle a day (Thermometers - Logic Puzzles on the App Store). Mercuro sends three, a Warm-Up, a Daily and a Challenge, each on a bigger board than the last.
When Thermometers - Logic Puzzles is the better fit
It has far more puzzles, over 9,000 against Mercuro's 660, with boards up to 17x17. It also has a dark mode and a warm paper look (Thermometers - Logic Puzzles on the App Store). If volume and huge boards are what you want, it is the better pick.
Switching over
Mercuro tops out at 12x12, so if you mostly play bigger grids it will feel small at the high end. In return you get a hint that names the next forced move and explains it, and two purchases you make once, if at all, in place of a membership.
Questions
Does Mercuro have a weekly or monthly plan?
No. Both purchases are one-time.
Does Mercuro have a dark mode?
Yes. Slate, one of the two themes you start with, is dark.
How big do Mercuro boards get?
Up to 12x12. The daily Challenge is between 10x10 and 12x12.
More guides
- How to play Thermometers puzzlesThree rules and a 4x4 solved move by move.
- 6×68×811×11Three new logic puzzles every dayWarm-Up, Daily, Challenge, and a two-week archive.
- $4.99onceA logic puzzle game with no subscription330 puzzles free. $2.99 or $4.99, paid once.
- Like Sudoku or nonograms? Try ThermometersWhat carries over, and the one rule that is new.
- Level packs$4.49 subscriptionPay onceA Grids of Thermometers alternativeNo packs, no subscription, three dailies a day.
- Mercuro overviewEvery feature, drawn and playable.
How Mercuro is built, the solver, generator and hint engine behind these puzzles.