Free42

HP-42S Simulator: advanced scientific programmable RPN calculator.

Thomas Okken · com.thomasokken.free42

Not rated yet 100K+ downloads v3.1.2 7.3 MB Android 4.0+ PEGI 3 · Everyone

Download APK 7.3 MB All versions

Signature matches the Google Play version Details

At a glance

Latest version: v3.1.2 (159)
Updated: Jun 17, 2026 (4 months ago)
APK size: 7.3 MB
Requires: Android 4.0+ (API 14)
CPU support: ARM 32-bit, ARM 64-bit
Category: Tools (app)
Listed since: Feb 25, 2021 (at least)
Permissions: 5 (3 sensitive)
Website: thomasokken.com/free42
Developer contact: [email protected]

About this APK

Free42 is an app by Thomas Okken in the Tools category, listed since at least February 2021. It includes native code for ARM 32-bit and ARM 64-bit, so it runs on practically every phone.

It asks for 5 permissions, 3 of them sensitive: precise location, approximate location and modify shared storage.

What's new in v3.1.2

CSLD? did not handle intervening XEQ/RTN. Fixed. FUNC did not detect previous FUNC/LNSTK/L4STK. Fixed.

Description

From the listing uploaded by “appupdater”.

Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer. It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image. Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2. All third-party code used in Free42 is either in the public domain, or licensed under terms compatible with GPLv2, or used with the authors' permission.

Security & authenticity

Security rating: Trusted

Signing certificate

Signature matches the Google Play version Checked by the source store on Jun 17, 2026.
Certificate issued to “Thomas Okken Software” This is the certificate of the Google Play version.

Store checks and file details

Developer signature verified Jun 17, 2026
Validated against Google Play Jun 17, 2026
Signed byCN=Thomas Okken, OU=OSS Development, O=Thomas Okken Software, L=North Brunswick, ST=NJ, C=US
Signing certificate (SHA-1)47:A7:FB:FF:9A:C0:6C:8A:9A:B1:3D:0D:95:41:A4:1C:DA:DA:ED:0D
File MD505cb7fc5bd395edba674704569c74a70
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 (5)

Free42 requests 5 permissions, 3 of them sensitive.

Approximate location Sensitive android.permission.ACCESS_COARSE_LOCATION
Modify shared storage Sensitive android.permission.WRITE_EXTERNAL_STORAGE
Precise location Sensitive android.permission.ACCESS_FINE_LOCATION
Control vibration android.permission.VIBRATE
Full network access android.permission.INTERNET

Required hardware & features

Basic touch input android.hardware.faketouch
Location android.hardware.location

Free42 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 Free42 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 05cb7fc5bd395edba674704569c74a70.