- SlotAlert: slot monitoring for your consulate, $9.99 one-time.
- Google Calendar: appointment events with location, confirmation numbers, and two alerts.
- Google Drive: per-trip document folders, shared with family if needed.
- Adobe Scan: free, consulate-grade PDF scans.
- Google Translate: offline packs for the application center's language.
Sources: U.S. State Department
Android's strength is the workflow between apps: scan the document, save it to the trip folder, attach the folder link to the calendar event. On appointment day, everything is two taps away. Set the calendar alert for the night before (document check) and one hour before (leave now). The most common appointment failure is not the consulate. It is traffic.