Slitherlink vs Pi 100 Challenge
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
Slitherlink
Solve logic puzzles by drawing a single loop around clues on a grid. Connect dots to form a continuous line, with no crossings or branches. Offers endless fun and intellectual challenge for puzzle enthusiasts.
- Draw a single continuous loop
- Surround numbered clues
- Pure logic, no math required
- Weekly bonus puzzles
- Multiple difficulty levels
- Auto complete clues
- Highlight link segment
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Surround each clue with lines to form one single loop! Each puzzle consists of a rectangular lattice of dots with some clues in various places. The object is to connect the dots surrounding each clue so that the number of lines equals the value of the clue and the lines around all clues form one continuous loop with no crossings or branches. Empty squares may be surrounded by any number of lines. Slitherlink are addictive loop-forming puzzles which were invented in Japan. Using pure logic and requiring no math to solve, these fascinating puzzles offer endless fun and intellectual entertainment to puzzle fans of all skills and ages. The game features 2-finger tapping for quick zoom, auto complete clues setting and a link segment highlighting option to help to avoid creating separate loops. To help see the puzzle progress, graphic previews in the puzzle list show the progress of all puzzles in a volume as they are being solved. A Gallery view option provides these previews in a larger format. For more fun, Slitherlink contains no ads and includes a Weekly Bonus section providing an extra free puzzle each week. PUZZLE FEATURES • 200 free Slitherlink puzzles • Extra bonus puzzle published free each week • Multiple difficulty levels from very easy to extremely hard • Grid sizes up to 16x22 • Puzzle library continuously updates with new content • Manually selected, top quality puzzles • Unique solution for each puzzle • Hours of intellectual challenge and fun • Sharpens logic and improves cognitive skills GAMING FEATURES • No ads • Unlimited check puzzle • Unlimited Undo and Redo • Auto complete clues • Highlight link segment • Quick zoom using 2-finger tap • Concurrently playing and saving multiple puzzles • Puzzle filtering, sorting and archiving options • Dark Mode support • Graphic previews showing puzzles progress as they are being solved • Portrait and landscape screen support (iPad only) • Track puzzle solving times • Backup & restore puzzle progress to iCloud ABOUT Slitherlink have also become popular under other names such as Fences, Loop the Loop, Loopy, Suriza, Dotty Dilemma and Number Line. Similar to Sudoku, Kakuro and Hashi, the puzzles are solved using logic alone. All puzzles in this app are produced by Conceptis Ltd. - the leading supplier of logic puzzles to printed and electronic gaming media all over the world. On average, more than 20 million Conceptis puzzles are solved each day in newspapers, magazines, books and online as well as on smartphones and tablets across the world. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.conceptispuzzles.com/index.aspx?uri=info/doc/220
Pi 100 Challenge
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Some people climb mountains, while others run marathons. You are challenging yourself to calculate Pi by hand. This app guides you through all the steps needed to compute Pi to 100 decimal places. Surprisingly enough, this doesn't require any complex math -- just basic addition, subtraction, multiplication and long division. Each page presents one problem to solve. Complete the problem, and move on to the next step. Take the Pi-100 Challenge, sharpen your mind, and calculate Pi. GameCenter integration allows you to track progress and achievements. Leaderboards allow you to race against your friends to see who can finish more digits, or solve for the digits faster.
Screenshots
Verdict
The clearest difference is price: Slitherlink at Free against Pi 100 Challenge's $0.99. Slitherlink also leads on iOS requirement (15.6 vs 17.0). Pi 100 Challenge's advantage is in-app purchases (none vs 13) and update cadence (every 3 weeks vs every 4 months). On ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Slitherlink is free to download; Pi 100 Challenge costs $0.99 up front. Slitherlink sells 13 one-off in-app purchases. Pi 100 Challenge asks for nothing beyond the download.
Slitherlink ships an update every 4 months, Pi 100 Challenge every 3 weeks. The most recent releases landed on October 19, 2026 and October 10, 2026 respectively.
| Parameter | Slitherlink | Pi 100 Challenge |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | 4.8 (457 ratings) — better | — |
| Positive reviews | 89.5% of reviews | — |
| Number of ratings | 457 — better | — |
| Update frequency | Every 4 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 7 MB | 11 MB |
| Age rating | 4+ | 4+ |
| Developer | Conceptis Ltd. | Ram Rao |
Bugs and requests
Slitherlink
Reported bugs
3 issues- App not loading properly for some users
- Freezing issues on login screen
- Incompatibility with older devices
Requested features
5 requests- Add a dark mode option
- Implement coloring/marking tools for loop segments
- Provide more free puzzle content
- Reduce pricing for puzzle packs
- Add a rewind/undo feature to go back to previous puzzle states
Pi 100 Challenge
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Slitherlink
- Medium Snacks 1$0.99
- Easy Variety 1$1.99
- Easy Variety - Large 1$1.99
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- Medium Variety 1$1.99
- Medium Variety - Large 1$1.99
- Hard Variety 1$1.99
- Easy Variety 2$1.99
- Medium Variety 2$1.99
- Hard Variety 2$1.99
- Big & Easy 1$1.99
- Big & Medium 1$1.99
- Hard Variety - Large 1$1.99
- Big & Tough 1$1.99
Pi 100 Challenge
No in-app purchases









