What are maps and location?
Location-aware apps read the device's GPS and often display a map. The location APIs give you the current position and updates as the user moves; map components render an interactive map with markers and regions for delivery, fitness, social, and travel features.
Why it matters
Location is a powerful, popular capability and a sensitive one. It drains battery, raises privacy concerns, and behaves differently per platform. Using it well — requesting only the precision you need, only when you need it — is both good engineering and a requirement to pass store review.
What to learn
- Foreground versus background location
- Accuracy levels and their battery cost
- Watching position versus a one-time read
- Rendering a map with markers and regions
- Location permissions, including "while using"
- Geocoding addresses to coordinates
- Privacy expectations and store rules
Common pitfall
Requesting high-accuracy, always-on background location when the feature only needs a rough position while the app is open. It drains battery, alarms users, and draws extra scrutiny from app review. Request the lowest accuracy and narrowest scope that works — usually foreground, "while using" — not the maximum.
Resources
Primary (free):
- Expo — Location · docs
- react-native-maps — Docs · docs
- Apple — Requesting location authorization · docs
Practice
Build a screen that requests "while using" location, reads the current position, and shows it on a map with a marker. Add a second marker and center the map region on the user. Done when it works with foreground permission and does not request background or maximum accuracy needlessly.
Outcomes
- Read current and watched location with appropriate accuracy.
- Render a map with markers and regions.
- Request the narrowest location permission that works.
- Respect battery and privacy in location features.