App Lock - Applock Fingerprint positions itself as a comprehensive privacy solution for Android devices, offering immediate protection for sensitive applications and personal data. Developed by Trusted Tools, the application enters a competitive market of privacy utilities with a straightforward value proposition: preventing unauthorized access to designated content through multiple authentication methods. The application's core functionality centers on selective app locking capabilities, supporting protection for social media platforms (WhatsApp, Instagram, Facebook), communication tools, gallery applications, and system utilities. Implementation occurs through three authentication modalities: numeric PIN codes, pattern drawing, and fingerprint recognition where supported by hardware. The locking mechanism activates immediately upon application selection, requiring authentication before granting access to protected content. Custom recovery questions provide additional security layers for account restoration scenarios. User experience demonstrates efficiency in setup and daily operation, with intuitive interface design enabling rapid application selection and configuration. The locking process operates seamlessly in background operations, triggering authentication prompts only when accessing protected applications. Real-world usage patterns indicate particular utility in shared device scenarios, parental control contexts, and professional environments requiring separation between personal and work applications. The absence of noticeable performance impact during routine operation contributes to consistent user experience. User feedback analysis reveals consistent praise for the application's comprehensive locking capabilities and customization options. Multiple reviews from user Sapna Panthari (July 15, 2025) highlight the ability to 'lock anything and customise recovery questions' while identifying a significant security limitation: protection circumvention through application deletion. This vulnerability represents a critical consideration for users requiring robust security against technically knowledgeable adversaries attempting to bypass protection measures. The application demonstrates notable strengths in accessibility and immediate privacy protection, particularly for casual security needs and social media privacy concerns. However, the identified vulnerability regarding application deletion limits its effectiveness against determined adversaries with physical device access. Ideal use cases include basic privacy maintenance in low-risk environments, parental monitoring scenarios, and temporary privacy measures rather than comprehensive security solutions requiring tamper-resistant protections.