How readings are taken

YANL combines direct readings from Android with calculations performed on the phone before data is shown in tiles or uploaded to the web.

Three source types

See the full list in the Metrics reference.

Polling and logging

• The app samples hardware metrics on a steady 1-second (1 Hz) tick.
• Every tick is written to the log, so the timeline is complete and evenly spaced. If a tick is missed, an explicit gap record marks the span.
• Each radio_sample carries derived_wallclock_ms for wall-clock replay; line datetimes on session_start / event use ISO-8601.
• Current captures use schema_version: 3; see Log file format (v3).
• You can disable categories (network, Wi‑Fi, location, Bluetooth, etc.) in logging settings; disabled data is not recorded.

For how readings are aged, when they’re blanked, and how the app behaves in aeroplane mode or with the screen off, see Data quality & real-world behaviour.

What the web viewer shows

The web replay viewer displays the same metric keys and thresholds as the Android app. Status colours (Good / Marginal / Poor) use the same bands on both platforms.

For cellular metrics, the web honours radio.*_state freshness: stale or missing modem readings appear as gaps on charts and greyed values on the Serving Cell tile.

Next

• Log file format (v3): record types and metric shapes
• Data quality & real-world behaviour: freshness, blanking, and tested scenarios
• Derived metrics: values calculated by the app
• Android & iPerf3 sources: official reference links
• Metrics reference: every metric with units and thresholds