# modlet > modlet is a development studio that focuses on building precision shopify apps ## Overview modlet's first app is called "Block PO Boxes & Lockers". It helps merchants prevent shipping errors and lost revenue by automatically identifying and blocking PO Box and modern logistics (locker) addresses at checkout. ## Key Features of "Block PO Boxes & Lockers" - **Revenue Protection**: Stops orders that cannot be shipped to PO Boxes (e.g., FedEx, UPS). - **Performance**: Lightweight and fast, ensuring no impact on store speed. Using Shopify Functions. - **Fair Pricing**: Simple, transparent pricing for merchants of all sizes. ## Global Capabilities of "Block PO Boxes & Lockers" modlet is optimized for international commerce, solving specific logistics challenges in various regions: - **India**: Reduces RTO (Return-to-Origin) on COD (Cash on Delivery) orders by validating complete addresses and blocking incomplete ones. Compatible with BlueDart. - **Mexico**: Blocks 'Ocurre' (Hold for Pickup) and invalid formats for Estafeta, DHL, and FedEx. - **Japan**: Handles 'Kyokudome' (Post Office Hold) and supports Yamato Transport & Sagawa Express validation. - **Germany**: Blocks 'Packstationen' to prevent delivery failures with DHL and UPS. - **UK**: Blocks BFPO (British Forces Post Office) addresses to prevent issues with DPD and Hermes. - **General**: Supports local carriers and address formats for 30+ locales. the app is internationalized into 15 locales, and it supports error messages in any language the store is configured for. ## Links - [Homepage](https://modlet.app) - [Privacy Policy](https://modlet.app/legal/privacy) - [Terms of Service](https://modlet.app/legal/terms) - [Support](https://modlet.app/support) - [Contact](mailto:contact@modlet.app)