Operational amplifiers notes
v3.3.0 · 9.5 MB · code 19
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File information
UpdatedSep 4, 2025
PublishedJan 11, 2020
Packagecom.apps.onebuttondev.opampcalculator
Versionv3.3.0 (19)
Size9.5 MB
MD510f2f5e2c5484cd2a8acb6f67a3ed93d
Min SDK21
Malware scanTRUSTED
Signature SHA166:DA:91:27:FA:E7:21:1E:07:94:AA:86:46:99:60:B7:00:D2:F4:E3
SignerCN=Guillermo Gerard, OU=One Button Development, O=One Button, L=Comodoro Rivadavia, ST=Chubut, C=AR
Total downloads10,000
This version10,000
DeveloperGuillermo Gerard
Age ratingEveryone
What's new in v3.3.0
v3.3.0
General updates and bug fixing. Major update using AndroidX
v3.2.3
Added privacy policy to comply with google's policies, bug fixes, added donate menu item.
v3.2.1
Added option to move to SD. Library updates.
v3.1.3
Library updates to comply with Google's policies
General updates and bug fixing. Major update using AndroidX
v3.2.3
Added privacy policy to comply with google's policies, bug fixes, added donate menu item.
v3.2.1
Added option to move to SD. Library updates.
v3.1.3
Library updates to comply with Google's policies
Security scan
TRUSTED
- Developer signature verified 2020-04-21
- Scanned for malware 2020-09-03 18:03:46
- Signature SHA1 66:DA:91:27:FA:E7:21:1E:07:94:AA:86:46:99:60:B7:00:D2:F4:E3
- File MD5 10f2f5e2c5484cd2a8acb6f67a3ed93d
How to install Operational amplifiers notes v3.3.0 on Android 5.0 Lollipop+
Takes about 2 minutes. You'll need roughly 9.5 MB of free storage.
- Grab com.apps.onebuttondev.opampcalculator_19.apk — hit the Download button above (9.5 MB). If your browser warns about APK files, choose Keep or Download anyway — that warning fires on every APK, not just this one.
- Trust your browser to install — on Android 8+ go to Settings → Apps → Special access → Install unknown apps, pick the app you downloaded with (Chrome, Firefox, Files, etc.), and flip Allow from this source. On older Android, toggle Unknown sources under Security.
- (Optional) Verify the file — compute the MD5 of the downloaded APK and make sure it matches 10f2f5e2c5484cd2…. Any difference means the file is corrupted or tampered — delete and re-download.
- Open the APK — tap the download notification, or find com.apps.onebuttondev.opampcalculator_19.apk in your Files app under Downloads, then tap it. Android's package installer will appear.
- Check the signer — the install screen will name the publisher. For this build it should read CN=Guillermo Gerard, OU=One Button Development, O=One Button, L=Comodoro Rivadavia, ST=Chubut, C=AR. If it doesn't match, cancel — you have the wrong file.
- Review permissions & tap Install — scroll the permission list, then confirm. If Play Protect flags it, tap Install anyway (this APK was scanned as TRUSTED).
- Done — open Operational amplifiers notes — tap Open on the install screen, or find the Operational amplifiers notes icon in your app drawer.
Common install errors for Operational amplifiers notes
- "App not installed" — usually means an older or differently-signed version is already on your device. Uninstall it first, then retry. Your data may be lost unless you back it up.
- "Parse error" — the APK is for a newer Android than yours. This version needs Android 5.0 Lollipop or later. Pick an older build from the versions list below.
- "There was a problem parsing the package" — the download was interrupted. Delete the file and re-download over Wi-Fi.