aCalendar - your calendar
Tapir Apps GmbH · Build 2.9.5
Static checks identify review items, not a guarantee of safety.
Overview
4 finding categories to review
aCalendar - your calendar (org.withouthat.acalendar) scored grade A, 92 out of 100, in a static scan of version 2.9.5 on 2026-10-12. It has no high or critical findings, and 4 lower-severity finding categories across 5 occurrences. 3 tracking SDKs are present in the package, which describes what ships, not what runs or what it sends. This is static analysis of a single build: it does not observe the app running and does not establish that any data is exposed.
Start with these findings
mediumShort signing key (RSA 1024-bit)1 occurrence
Interpretation & review guidance
The signing key is shorter than the modern 2048-bit RSA minimum. Short keys are cryptographically weaker; a release should re-key to at least RSA-2048 (or an EC key).
- Evidence
- 1 recorded occurrence in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
lowData Safety label omits Calendar2 occurrences
Interpretation & review guidance
The app's Google Play Data Safety label omits a data category it can actually access — a permission it requests, or an advertising/device identifier it references. Under-declaring collection is a Play policy issue and a COPPA/privacy concern. This is a static signal: a requested permission is capability, not proof of collection — confirm against runtime behavior.
How often Data Safety labels disagree with the package →
- Evidence
- 2 recorded occurrences in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
lowGoogle API key (client-shipped; restriction unverified)1 occurrence
Interpretation & review guidance
Android apps are designed to ship Google API keys in the client; Google restricts them by app signing certificate + enabled API. This is only a problem if the key is left unrestricted — presence alone is expected, not an exposure.
- Evidence
- 1 recorded occurrence in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
Build & components
69 components recorded. Certificate parsing does not validate APK signature integrity.
Inspect build evidence →Findings
4 categories · 5 occurrences. Severity totals describe categories. Expand a finding for interpretation and review guidance.
mediumShort signing key (RSA 1024-bit)1 occurrence
Interpretation & review guidance
The signing key is shorter than the modern 2048-bit RSA minimum. Short keys are cryptographically weaker; a release should re-key to at least RSA-2048 (or an EC key).
- Evidence
- 1 recorded occurrence in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
Evidence preview
- Evidence type
- Signing metadata
- Representative location
META-INF/signing:key- Recorded match
RSA-1024- Detector rule
signing- Recorded file locations
META-INF/signing:key
1 recorded findings have inspectable metadata. Duplicate matches may share a representative location.
Review whether this belongs to intended app functionality or a bundled library. A static match does not establish runtime impact.
Preview evidence and Pro toolsSearch recorded evidence and save private review notes with Pro. $99/month plus applicable tax.
lowData Safety label omits Calendar2 occurrences
Interpretation & review guidance
The app's Google Play Data Safety label omits a data category it can actually access — a permission it requests, or an advertising/device identifier it references. Under-declaring collection is a Play policy issue and a COPPA/privacy concern. This is a static signal: a requested permission is capability, not proof of collection — confirm against runtime behavior.
How often Data Safety labels disagree with the package →
- Evidence
- 2 recorded occurrences in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
Evidence preview
- Evidence type
- Static string match
- Representative location
data-safety:Calendar- Recorded match
Pattern recorded; identifying value redacted.
2 recorded findings have inspectable metadata. Duplicate matches may share a representative location.
Review whether this belongs to intended app functionality or a bundled library. A static match does not establish runtime impact.
Preview evidence and Pro toolsSearch recorded evidence and save private review notes with Pro. $99/month plus applicable tax.
lowGoogle API key (client-shipped; restriction unverified)1 occurrence
Interpretation & review guidance
Android apps are designed to ship Google API keys in the client; Google restricts them by app signing certificate + enabled API. This is only a problem if the key is left unrestricted — presence alone is expected, not an exposure.
- Evidence
- 1 recorded occurrence in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
Evidence preview
- Evidence type
- Static string match
- Representative location
AndroidManifest.xml- Recorded match
AIza•••••••• (21–40 chars, redacted)- Detector rule
google_api_key- Recorded file locations
AndroidManifest.xml
1 recorded findings have inspectable metadata. Duplicate matches may share a representative location.
Review whether this belongs to intended app functionality or a bundled library. A static match does not establish runtime impact.
Preview evidence and Pro toolsSearch recorded evidence and save private review notes with Pro. $99/month plus applicable tax.
infoApplication data is backup-enabled1 occurrence
Interpretation & review guidance
The app allows Android backups (android:allowBackup="true"). App data can then be extracted via adb backup on many devices — a concern if the app stores tokens or personal/health/payment data locally. Common and low-severity, but worth disabling for sensitive apps.
- Evidence
- 1 recorded occurrence in the analyzed APK. These are distinct stored findings, not a count of every source match.
- Verification
- Static detection; current reachability is not established.
Evidence preview
- Evidence type
- Parsed app configuration
- Representative location
AndroidManifest.xml- Recorded match
android:allowBackup="true"- Detector rule
manifest- Recorded file locations
AndroidManifest.xml
1 recorded findings have inspectable metadata. Duplicate matches may share a representative location.
Review whether this belongs to intended app functionality or a bundled library. A static match does not establish runtime impact.
Preview evidence and Pro toolsSearch recorded evidence and save private review notes with Pro. $99/month plus applicable tax.
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Privacy signals
Capabilities and bundled software do not prove that data was collected or transmitted.
Contacts Calendar Accounts
Requested permission inventory (22)
Data collection & flow (privacy signal, not part of the grade)
- Persistent-identifier APIs referenced in code (Advertising ID (AAID), Android ID, Device ID / IMEI) with 2 analytics/ad SDK(s) present — the mechanism used for cross-app profiling.
- Calendar, Contacts, Personal info, Photos & files data requested with third-party analytics/ad SDKs present.
This maps what the app can access (permissions it requests, identifier APIs its code references) to the third parties bundled in it. It reflects capability and SDK presence — not proof that a specific value was transmitted.
Data Safety: declared vs observed (Play label vs our analysis)
We compare the developer's Google Play Data Safety declaration with what the binary can actually do (permissions it requests, identifier APIs and third-party SDKs it ships). A mismatch is a capability signal to confirm — a requested permission is not proof of collection.
Trackers & SDKs (3 detected · privacy signal, not part of the grade)
Build & components
Scanned build 2.9.5. Store metadata may describe a newer release.
380797689aa6c223f9e77f7832aa0c15dcafc9f4643eff4d629ef786d8ca641cSigning certificate (who signed this build — factual, not part of the grade)
6e:34:34:74:69:12:53:42:81:a9:7d:9d:b0:c0:5d:02:b7:c8:7b:9c:44:86:aa:53:46:58:bd:42:fd:a4:3a:1dThe certificate fingerprint identifies the parsed signing certificate. Knowing this public fingerprint does not establish ownership or validate the APK signature.
Component inventory
69 components. Advisory matching covers a curated set; no match is not proof that a component is vulnerability-free.
| Component | Version | Advisory matches |
|---|---|---|
androidx.activity:activity | 1.8.0 | None recorded |
androidx.activity:activity-ktx | 1.8.0 | None recorded |
androidx.annotation:annotation-experimental | 1.4.1 | None recorded |
androidx.appcompat:appcompat | 1.7.1 | None recorded |
androidx.appcompat:appcompat-resources | 1.7.1 | None recorded |
androidx.browser:browser | 1.3.0 | None recorded |
androidx.cardview:cardview | 1.0.0 | None recorded |
androidx.constraintlayout:constraintlayout | 2.2.1 | None recorded |
androidx.coordinatorlayout:coordinatorlayout | 1.3.0 | None recorded |
androidx.core:core | 1.16.0 | None recorded |
androidx.core:core-ktx | 1.16.0 | None recorded |
androidx.core:core-viewtree | 1.0.0 | None recorded |
androidx.cursoradapter:cursoradapter | 1.0.0 | None recorded |
androidx.customview:customview | 1.1.0 | None recorded |
androidx.customview:customview-poolingcontainer | 1.0.0 | None recorded |
androidx.databinding:viewbinding | 8.7.3 | None recorded |
androidx.documentfile:documentfile | 1.0.0 | None recorded |
androidx.dynamicanimation:dynamicanimation | 1.0.0 | None recorded |
androidx.emoji2:emoji2 | 1.3.0 | None recorded |
androidx.emoji2:emoji2-views-helper | 1.3.0 | None recorded |
androidx.exifinterface:exifinterface | 1.3.6 | None recorded |
androidx.fragment:fragment | 1.5.7 | None recorded |
androidx.fragment:fragment-ktx | 1.3.6 | None recorded |
androidx.interpolator:interpolator | 1.0.0 | None recorded |
androidx.legacy:legacy-support-core-utils | 1.0.0 | None recorded |
androidx.lifecycle:lifecycle-livedata | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-livedata-core | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-livedata-core-ktx | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-process | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-runtime | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-runtime-ktx | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-service | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-viewmodel | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-viewmodel-ktx | 2.8.7 | None recorded |
androidx.lifecycle:lifecycle-viewmodel-savedstate | 2.8.7 | None recorded |
androidx.loader:loader | 1.1.0 | None recorded |
androidx.localbroadcastmanager:localbroadcastmanager | 1.0.0 | None recorded |
androidx.palette:palette | 1.0.0 | None recorded |
androidx.palette:palette-ktx | 1.0.0 | None recorded |
androidx.preference:preference | 1.2.1 | None recorded |
androidx.preference:preference-ktx | 1.2.1 | None recorded |
androidx.print:print | 1.0.0 | None recorded |
androidx.profileinstaller:profileinstaller | 1.4.0 | None recorded |
androidx.recyclerview:recyclerview | 1.4.0 | None recorded |
androidx.room:room-ktx | 2.7.2 | None recorded |
androidx.room:room-runtime | 2.7.2 | None recorded |
androidx.savedstate:savedstate | 1.2.1 | None recorded |
androidx.savedstate:savedstate-ktx | 1.2.1 | None recorded |
androidx.slidingpanelayout:slidingpanelayout | 1.2.0 | None recorded |
androidx.sqlite:sqlite | 2.5.1 | None recorded |
androidx.sqlite:sqlite-framework | 2.5.1 | None recorded |
androidx.startup:startup-runtime | 1.1.1 | None recorded |
androidx.tracing:tracing | 1.2.0 | None recorded |
androidx.tracing:tracing-ktx | 1.2.0 | None recorded |
androidx.transition:transition | 1.5.0 | None recorded |
androidx.vectordrawable:vectordrawable | 1.1.0 | None recorded |
androidx.vectordrawable:vectordrawable-animated | 1.1.0 | None recorded |
androidx.versionedparcelable:versionedparcelable | 1.1.1 | None recorded |
androidx.viewpager2:viewpager2 | 1.1.0-beta02 | None recorded |
androidx.viewpager:viewpager | 1.0.0 | None recorded |
androidx.webkit:webkit | 1.12.1 | None recorded |
androidx.window:window | 1.0.0 | None recorded |
androidx.work:work-runtime | 2.10.3 | None recorded |
androidx.work:work-runtime-ktx | 2.10.3 | None recorded |
com.google.android.material:material | 1.12.0 | None recorded |
com.squareup.okhttp3:okhttp | 4.12.0 | None recorded |
kotlinx:coroutines_android | 1.10.2 | None recorded |
kotlinx:coroutines_core | 1.10.2 | None recorded |
kotlinx:coroutines_play_services | 1.10.2 | None recorded |
About this app · store information
About this app
aCalendar - makes your day, week and month!
Screenshots
Scan history
Each row is an observed scan. Gaps between scans do not establish how long a finding existed.
| Scanned (UTC) | Build | Score | Grade |
|---|---|---|---|
| 2026-10-12 09:41 UTC | 2.9.5 | 92 | A |
| 2026-10-05 09:40 UTC | 2.9.5 | 92 | A |
| 2026-09-28 09:40 UTC | 2.9.5 | 91 | A |
| 2026-09-14 12:34 UTC | 2.9.5 | 91 | A |
| 2026-09-06 02:33 UTC | 2.9.5 | 91 | A |
Export & share
Exports describe the recorded assessment. Signed evidence proves origin and integrity, not completeness or safety.
Coverage & gap matrix · Verify signed evidence
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