What is the best alternative to Altimeter GPS & Barometer on iPhone?

Altitude & Elevation, S tier, #1 in altimeter.

Is there a free alternative to Altimeter GPS & Barometer?

Yes: Altitude & Elevation (S tier, #1) is free to download.

Yes. 5 apps rank above it in altimeter: Altitude & Elevation (#1), Barometer & Altimeter & Thermo (#2), Altimeter - Altitude & Compass (#3) and more.

Altimeter GPS & Barometer is B tier, #6 of 7 in altimeter. Here is everything that competes with it on iPhone, in tier order.

1
Altitude & ElevationShigher tier
Free download · ★ 4.6 · 43,447 ratings · score 95
Shows altitude, latitude and longitude, records trips including offline, and offers session analytics with PDF export.
2
Barometer & Altimeter & ThermoShigher tier
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 & CompassShigher tier
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 MapAhigher tier
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 AltitudeAhigher tier
Free download · ★ 4.8 · 26,861 ratings · score 82
Shows GPS latitude, longitude, altitude, barometric pressure and water boiling point for your current location.
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 Altimeter GPS & Barometer on iPhone?: Altitude & Elevation, S tier, #1 in altimeter.
Is there a free alternative to Altimeter GPS & Barometer?: Yes: Altitude & Elevation (S tier, #1) is free to download.
Does anything rank above Altimeter GPS & Barometer?: Yes. 5 apps rank above it in altimeter: Altitude & Elevation (#1), Barometer & Altimeter & Thermo (#2), Altimeter - Altitude & Compass (#3) and more.