ON Protractor
v2.0 · 2 MB · code 4
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File information
UpdatedApr 30, 2015
PublishedApr 30, 2015
Packagecom.potatotree.onprotractor
Versionv2.0 (4)
Size2 MB
MD5b3d121e3a5f5453a1e1b7f54e216c064
Min SDK7
Malware scanWARNING
Signature SHA128:44:27:0C:4D:78:B4:26:8E:84:EA:80:1C:20:D9:09:7E:F1:8D:75
SignerCN=hong yih piao, OU=potatotreesoft, O=potatotreesoft, L=penang, ST=penang, C=60
Total downloads500,000
This version500,000
DeveloperPotatotreeSoft
Age ratingEveryone
What's new in v2.0
Update v2.0
- Add [Flash Light] function in camera mode
- Add sensor calibration function
- Minor bug fixes
Update v1.2
- Redesign menu screen for main menu button
- Bug fixed: User manual cannot be displayed
- Code optimization / File size reduced
- Add [Flash Light] function in camera mode
- Add sensor calibration function
- Minor bug fixes
Update v1.2
- Redesign menu screen for main menu button
- Bug fixed: User manual cannot be displayed
- Code optimization / File size reduced
Security scan
WARNING
- Developer signature verified 2025-03-10
- Scanned for malware 2020-11-10 17:25:10
- Signature SHA1 28:44:27:0C:4D:78:B4:26:8E:84:EA:80:1C:20:D9:09:7E:F1:8D:75
- File MD5 b3d121e3a5f5453a1e1b7f54e216c064
How to install ON Protractor v2.0 on Android API 7+
Takes about 2 minutes. You'll need roughly 2 MB of free storage.
- Grab com.potatotree.onprotractor_4.apk — hit the Download button above (2 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 b3d121e3a5f5453a…. Any difference means the file is corrupted or tampered — delete and re-download.
- Open the APK — tap the download notification, or find com.potatotree.onprotractor_4.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=hong yih piao, OU=potatotreesoft, O=potatotreesoft, L=penang, ST=penang, C=60. 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 WARNING).
- Done — open ON Protractor — tap Open on the install screen, or find the ON Protractor icon in your app drawer.
Common install errors for ON Protractor
- "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 API 7 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.