# 21 Skidoo — Card Counting Puzzler

> Blackjack-inspired card counting puzzle game for iOS. (iPhone/iPad app by James Ho.)

- Source: https://appshunter.io/ios/app/21-skidoo/id1672805689 (this page in markdown: same URL + `.md`)
- Developer: [James Ho](https://appshunter.io/developer/1672805691)
- Category: Games, Card, Puzzle
- Price: Free
- Rating: 5.00/5 from 8 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 14 · 45 MB
- Languages: English
- Released: 2023-03-07
- Data updated: 2026-06-10
- Monetization: ad-supported
- User reviews in markdown: https://appshunter.io/ios/app/21-skidoo/id1672805689/reviews.md

## What is 21 Skidoo?

21 Skidoo brings a new twist to the classic game of Blackjack. In this card counting puzzler you'll add cards together in any direction to make 21. Fill the entire board without any 21s and you'll lose. Challenge yourself now with this simple and addictive card game. Can you make it through an entire deck? How about 5?

## Key features

- Card counting mechanics
- Board clearing puzzles
- Blackjack twist
- Addictive gameplay
- Single player challenge

## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/21-skidoo/id1672805689/reviews.md

### 5/5 — Great Game James

*2024-05-12*

👍👍👍

### 5/5 — GREAT GAME!

*2023-03-30*

I usually don’t play many card games because the rules are too complicated. This game however is super simple and easy to learn. It is super addicting. I was playing for at least an hour without even realizing time passed. It’s also a great way to way to keep your brain active with some simple math. All around great game and I have no complaints.

**Developer response:** Thank you so much for taking the time to play and comment on my game. I'm so glad you enjoyed it!

### 5/5 — 👍

*2023-03-18*

This game is so addicting

**Developer response:** Glad you enjoyed it!

### 5/5 — Give it a try!

*2023-03-12*

Creative concept with cards; highly recommended.

**Developer response:** Thanks for the comments!

## Frequently asked questions about 21 Skidoo

### What is 21 Skidoo?

21 Skidoo is a card counting puzzle game for iPhone and iPad. It challenges players to add cards in any direction to make 21 and clear the board without creating any unwanted 21s.

### How do you play 21 Skidoo?

You play by tapping or swiping cards to add them together in any direction. The goal is to make combinations that equal 21 to clear them from the board. You lose if you fill the board with unplayable cards.

### Is 21 Skidoo free to play?

Yes, 21 Skidoo is free to download and play. It is supported by advertisements, as indicated by its monetization model.

### Does 21 Skidoo have ads?

Yes, 21 Skidoo contains advertisements. It is listed as an ad-supported application.

### What devices can I play 21 Skidoo on?

21 Skidoo is available on iPhone and iPad devices. It is designed for iOS users.

### How often is 21 Skidoo updated?

The latest version of 21 Skidoo is 1.0.12, which was last updated on May 1, 2023. Updates typically bring bug fixes and improvements.

### What is the age rating for 21 Skidoo?

21 Skidoo has an age rating of 4+, making it suitable for a wide range of players.

### Can I play 21 Skidoo offline?

While the description doesn't explicitly state offline play, many puzzle games of this nature are playable without an internet connection. However, ads may require connectivity.

## Version history (last 5 releases)

### 1.0.12 — 2023-05-01

Fixed a mathematics issue.
Fixed a typo.
Fixed a visual transition glitch.

### 1.0.10 — 2023-04-05

Fixed audio bug

### 1.0.9 — 2023-03-28

Fixed a counting error concerning multiple Ace cards in the same row/column.

### 1.0.8 — 2023-03-18

Fixing unintended behaviors from last update.
Added Review Request for players.

### 1.0.5 — 2023-03-12

Fixed issue with app losing/returning focus.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*