Table 2

App privacy-related and security-related evaluation methods and results

Privacy policySocial mediaPermissions requestedData security
MethodsResultsMethodsResultsMethodsResultsMethodsResults
Bry et al43Evaluated app store page and/or downloaded app manuallyPrivacy policy presence: Less than 5% of apps    Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: Less than 5% of apps
Cheng et al24      Evaluated app store page and/or downloaded app manuallyInvestigator-developed security assessment scale: 6% of apps rated as excellent; 10% of apps rated as good
Das et al20Statistics calculated with web-based readability calculatorPrivacy policy readability: average reading grade level (12.8) higher than average US adult level (8.0)      
Liu et al22  Comparison of app library package names with libraries relevant to social networksPotential for social medial sharing: 20% of appsExamination of privacy grade as listed in online crowdsourced datasetPotential for permission requests: 82% of apps use few permissions for unusual purposes; 10% may use permissions in this way  
Meyer et al23  Evaluated app store page and/or downloaded app manuallySocial media links: 14% of appsEvaluated app store page and/or downloaded app manuallyPermission requests:
100% of apps Requests for notifications (100%), files/photo storage (53%), phone (13%), microphone (8%), camera (7%); and location (4%).		  
Musgrave et al50      Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 90% of apps required logins; 70% required passwords
Reyes et al18      Automated analysis of whether data transmissions are protectedData encryption: 40% of apps do not use TLS*
Robinson et al53  Evaluated app store page and/or downloaded app manuallySocial media links: 63% of apps  Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 0% of apps
Sardi et al21Evaluated app store page and/or downloaded app manuallyPrivacy policy presence: 63% of apps
Privacy policy content:
27% of privacy policies complied with international and federal laws including COPPA†, GDPR‡ and HIPAA§.		Evaluated app store page and/or downloaded app manuallySocial media links:
31% of apps		  Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 29% of apps
Cloud storage backup option: 8% of apps
Schoeppe et al54  Evaluated app store page and/or downloaded app manuallySocial media links:
60% of apps		  Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 20% of apps
Schoffman et al55  Evaluated app store page and/or downloaded app manuallySocial media links:
16% of apps		    
Virani et al58Evaluated app store page and/or downloaded app manuallyPrivacy policy presence: 100% of apps    Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 33%–100% of apps
Weber et al59  Evaluated app store page and/or downloaded app manuallySocial media links:
Less than or equal to 35% of apps		  Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 70% of apps
Zarnowiecki et al63  Evaluated app store page and/or downloaded app manuallySocial media links:
25% of apps		  Evaluated app store page and/or downloaded app manuallyLogin and/or password presence: 0% of apps

  • *Transport Layer Security.

  • †Children’s Online Privacy Protection Act.

  • ‡General Data Protection Regulation.

  • §Health Insurance Portability and Accountability Act.