Four By 21

Solitaire meets Blackjack. Try to create four stacks of cards equalling 21.

Words and Maps · net.aharm.fourby21

Not rated yet 50K+ downloads v7.0 11.3 MB Android 8.0+ PEGI 3 · Everyone

Download APK 11.3 MB All versions

Signature matches the Google Play version Details

At a glance

Latest version: v7.0 (44)
Updated: Aug 29, 2025 (1 year ago)
APK size: 11.3 MB
Requires: Android 8.0+ (API 26)
CPU support: Any (no native code)
Category: Card (game)
Listed since: Mar 20, 2021 (at least)
Permissions: 9
Website: aharm.net
Developer contact: [email protected]
Privacy: Developer's privacy policy

About this APK

Four By 21 is a game by Words and Maps in the Card category, listed since at least March 2021. It has no native code, so it runs on any Android processor.

It asks for 9 permissions, none of them sensitive. The game can read the advertising ID that ad and analytics services use.

Description

From the listing uploaded by “appupdater”.

Four By 21: Solitaire meets Blackjack in this fast-paced single-player game. You are dealt one card at a time. Choose one of the four stacks to place the card. When the card values in a stack add up to exactly 21, that stack is cleared and you will score a point. If a stack value is over 21, that stack is busted. The game is over if you bust 5 times, or run out of time on the clock. Bonus points are given for consecutive stacks cleared. Brought to you by the makers of Pressed For Words!

Security & authenticity

Security rating: Trusted

Signing certificate

Signature matches the Google Play version Checked by the source store on Aug 29, 2025.
Certificate issued to “Alexander Harm” This is the certificate of the Google Play version.

Store checks and file details

Developer signature verified Aug 29, 2025
Validated against Google Play Aug 29, 2025
Signed byCN=Alexander Harm, L=Medford, ST=MA, C=US
Signing certificate (SHA-1)89:CD:18:1F:BD:48:F5:4E:96:2B:ED:35:48:47:B9:F0:21:21:A5:BF
File MD5a85ae8c5c2e7a486b667b2d498f07ee0
Uploaded by “appupdater” Gold tier · 117,810 followers · uploading since 2020

Scans and ratings come from the source store; the certificate comparisons are AAPKs's own, made from the files' published signatures. AAPKs doesn't scan files itself — compare the MD5 and signer after downloading.

Permissions (9)

Four By 21 requests 9 permissions, none of them sensitive.

Access adservices ad id android.permission.ACCESS_ADSERVICES_AD_ID
Access adservices attribution android.permission.ACCESS_ADSERVICES_ATTRIBUTION
Access adservices topics android.permission.ACCESS_ADSERVICES_TOPICS
Advertising ID com.google.android.gms.permission.AD_ID
Full network access android.permission.INTERNET
Internal broadcast protection (app-defined) net.aharm.fourby21.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Prevent the device from sleeping android.permission.WAKE_LOCK
Run foreground services android.permission.FOREGROUND_SERVICE
View network connections android.permission.ACCESS_NETWORK_STATE

Four By 21 APK: questions and answers

Can I install this APK over the version I already have?

Yes, if your installed copy is older. It is signed like the Google Play version, so Android installs it as an update and keeps your data.

Is the Four By 21 APK safe?

No one can promise that a file is safe, but some things can be checked. The source store rates this file Trusted. Its signature matches the Google Play version. After downloading, check that the file's MD5 is a85ae8c5c2e7a486b667b2d498f07ee0.