What is the best alternative to Altitude & Elevation on iPhone?

Barometer & Altimeter & Thermo, S tier, #2 in altimeter.

Is there a free alternative to Altitude & Elevation?

Yes: Barometer & Altimeter & Thermo (S tier, #2) is free to download, with in-app purchases.

No. Altitude & Elevation is #1 in altimeter.

Altitude & Elevation is S tier, #1 of 7 in altimeter. Here is everything that competes with it on iPhone, in tier order.

2
Barometer & Altimeter & ThermoS
Free + IAP · ★ 4.8 · 9,616 ratings · score 91
Measures atmospheric pressure and altitude, using GPS, device sensors and nearby weather station data.
3
Altimeter - Altitude & CompassS
Free download · ★ 4.6 · 8,454 ratings · score 90
Free iOS app with altitude, weather, compass, activity tracking, binoculars, and an SOS alert feature in one place.
4
Elevation - Altimeter MapA
Free download · ★ 4.5 · 5,485 ratings · score 84
Shows elevation for map locations and your current position using online data, GPS, or the device barometer.
5
My AltitudeA
Free download · ★ 4.8 · 26,861 ratings · score 82
Shows GPS latitude, longitude, altitude, barometric pressure and water boiling point for your current location.
6
Altimeter GPS & BarometerB
Free + IAP · ★ 4.6 · 2,193 ratings · score 79
Offline altimeter, GPS and barometer tool with compass, speedometer, address display and sunrise/sunset times for.
7
Compass & AltimeterC
Free + IAP · ★ 4.6 · 2,475 ratings · score 62
Compass app showing GPS coordinates, altitude, weather, air and magnetic field data, GPS speed, and saved location.

What is the best alternative to Altitude & Elevation on iPhone?: Barometer & Altimeter & Thermo, S tier, #2 in altimeter.
Is there a free alternative to Altitude & Elevation?: Yes: Barometer & Altimeter & Thermo (S tier, #2) is free to download, with in-app purchases.
Does anything rank above Altitude & Elevation?: No. Altitude & Elevation is #1 in altimeter.