Prot-On
v3.5.1 · 16 MB · code 57
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File information
UpdatedDec 8, 2025
PublishedMar 18, 2021
Packagecom.proton
Versionv3.5.1 (57)
Size16 MB
MD5a36ad64b922a128abd8360c923a76fe0
Min SDK22
ABIsx86, x86-64, armeabi-v7a, arm64-v8a
Malware scanTRUSTED
Signature SHA104:A8:A4:4D:35:47:42:D6:99:A7:9C:65:BD:44:94:4F:FE:7E:38:9C
SignerCN=proton.prot-on.com, OU=Proteccion On-line SL, O=Proteccion On-line SL, L=Madrid, ST=Spain, C=ES
Total downloads10,000
This version10,000
DeveloperProtección On-Line
Age ratingEveryone
What's new in v3.5.1
Update communication requirements with Prot-On server
Removed the request for MANAGE_EXTERNAL_STORAGE permission
Removed the request for MANAGE_EXTERNAL_STORAGE permission
Security scan
TRUSTED
- Developer signature verified 2025-12-08
- Signature SHA1 04:A8:A4:4D:35:47:42:D6:99:A7:9C:65:BD:44:94:4F:FE:7E:38:9C
- File MD5 a36ad64b922a128abd8360c923a76fe0
How to install Prot-On v3.5.1 on Android 5.1 Lollipop+
Takes about 2 minutes. You'll need roughly 16 MB of free storage.
- Grab com.proton_57.apk — hit the Download button above (16 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 a36ad64b922a128a…. Any difference means the file is corrupted or tampered — delete and re-download.
- Open the APK — tap the download notification, or find com.proton_57.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=proton.prot-on.com, OU=Proteccion On-line SL, O=Proteccion On-line SL, L=Madrid, ST=Spain, C=ES. 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 Prot-On — tap Open on the install screen, or find the Prot-On icon in your app drawer (this build targets x86/x86-64/armeabi-v7a/arm64-v8a devices).
Common install errors for Prot-On
- "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 5.1 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.
- Works on one phone but not another — this build ships x86/x86-64/armeabi-v7a/arm64-v8a native code. Devices with a different CPU will reject it.