Comparison

MileagePlus X vs Terrestream

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

MileagePlus X

Earn United MileagePlus award miles on everyday purchases. Discover nearby merchants, buy eGift cards, and browse curated deals. Track your miles as they post directly to your account with a refreshed, intuitive design.

Highlights
  • Earn award miles on purchases
  • Discover nearby merchants
  • Buy eGift cards
  • Browse curated deals
  • Track miles earned
  • Intuitive design
Features
Read full description

The new and improved MileagePlus X app is here, redesigned to make earning United® MileagePlus® award miles easier and smoother than ever. Explore a refreshed experience that brings shopping, dining and offers together in one place. Discover nearby merchants, buy eGift cards or browse curated deals to earn miles on everyday purchases. See earn rates before you shop, track your miles as they post directly to your MileagePlus® account and enjoy a cleaner, more intuitive design that puts your rewards front and center. Whether you’re grabbing coffee, shopping online or dining out, the new MileagePlus X app makes every purchase more rewarding.

About

Terrestream

Monitor your home's indoor air quality and receive actionable guidance. Understand how outdoor conditions impact your air and make informed decisions about ventilation and filtration.

Highlights
  • Real-time indoor air quality readings
  • Outdoor condition integration
  • Actionable ventilation guidance
  • Home screen widgets
  • Apple Watch companion app
  • Historical air quality data
  • Notification history
Features
Read full description

UNDERSTAND YOUR AIR. KNOW WHAT TO DO NEXT. Terrestream is the companion app for Terrestream indoor-air sensors. See what is changing in your home, understand the outdoor conditions that matter, and get a practical next step. Before you open a window, Terrestream considers both sides of it. Indoor readings and outdoor air quality, smoke, pollen, and weather help you decide when to ventilate, run filtration, investigate a possible indoor source, or keep watching. YOUR HOME, AT A GLANCE Today brings together your home's Air Index, the room that needs attention, and current guidance. Home Screen widgets put room air, whole-home conditions, window guidance, and comfort within easy reach. Choose the sizes and rooms that suit you, then tap through for more detail. Reading ages and unavailable states help you tell recent information from an older observation. AIR INSIGHTS ON YOUR WRIST The Apple Watch companion makes it easy to check your home and rooms, review window guidance, and follow an airing session. Add Terrestream to your Smart Stack or a supported watch face for quick access. The Watch app works with Terrestream on your iPhone. SEE WHAT CHANGED Compare rooms and explore 8h, 24h, or 7d of history. Inspect actual readings, choose the signals you want to see, and zoom into a change. Air-quality signals and temperature, humidity, and pressure share one timeline, with separate scales. A weekly heat map opens at the latest available reading and helps reveal patterns over time. Notification history brings your recent messages together by room and time. Review the original message and its recorded follow-up without confusing an earlier alert with today's conditions. GUIDANCE THAT FOLLOWS THE EVIDENCE Terrestream connects readings, room differences, and changes over time to explain possible causes and suggest useful actions. It distinguishes a brief rise from continuing accumulation or recovery, and builds ventilation history from independent CO₂ declines. These patterns help guide investigation; they do not identify a specific chemical or prove a ventilation fault. Use the Air view to compare outdoor conditions and forecast windows before bringing outside air in. Temperature and humidity are considered alongside air quality. Wildfire-smoke information and indoor particle readings help inform advice about closing windows and running filtration. READINGS THAT MATTER Follow CO₂, calculated IAQ, particles, VOC and NOx indices, temperature, humidity, pressure, and ambient light. VOC and NOx are relative indices that show changes over time; they do not identify individual chemicals. Pair a compatible sensor over Bluetooth, connect it to Wi-Fi, organize your rooms, and manage notification preferences and device controls. Home Assistant and MQTT integrations connect your sensor with compatible local dashboards and automations. The basic mobile app is included with your sensor. An optional Pro subscription adds longer history and advanced insights. YOUR PRIVACY Location access is optional. See our Privacy Policy for details about the information we collect, how service providers help operate Terrestream, and your privacy choices. WHAT YOU NEED Indoor readings require a compatible Terrestream sensor, sold separately, and a Terrestream account. Cloud features require internet access; the sensor uses 2.4 GHz Wi-Fi and Bluetooth during setup. Outdoor information varies by location, availability, and freshness. Widget refresh timing is managed by the operating system. Terrestream is informational, not a medical or life-safety device. It is not a smoke, fire, carbon monoxide, radon, or gas-leak detector. Keep your required alarms and do not rely on Terrestream in an emergency. Terms & Conditions: https://terrestream.com/legal/terms Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

MileagePlus X4 screens
Terrestream4 screens

Verdict

The call

The clearest difference is update cadence: Terrestream at every 3 days against MileagePlus X's monthly. Terrestream also leads on rating (5.0 vs 4.8) and device support (3 vs 1). MileagePlus X's advantage is ratings volume (21K vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Terrestream holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: MileagePlus X has 21K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

MileagePlus X ships an update monthly, Terrestream every 3 days. The most recent releases landed on November 5, 2026 and October 30, 2026 respectively.

Scorecard4 real differences · 6 level
MileagePlus X versus Terrestream: the parameters behind the verdict, then further details
ParameterMileagePlus XTerrestream
PriceFreeFree
Rating4.8 (21K ratings)5.0 (1 ratings) — better
Positive reviews21.7% of reviews—
Number of ratings21K — better1
Update frequencyMonthlyEvery 3 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhoneiPhone, Mac, Apple Watch — better
Requires iOS18.218.0 — better
Further details — not scored
Size58 MB19 MB
Age rating17+4+
DeveloperUALTerrestream

Customer experience

MileagePlus X

All ratings20,537 ratings
Positive94.4%
Neutral1.7%
Negative3.8%
Written reviews254 reviews
Positive21.7%
Neutral7.5%
Negative70.9%

Terrestream

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

MileagePlus X

Reported bugs

3 issues
  • Recurring transaction decline issues
  • Inconsistent tracking of earned miles
  • Glitches with gift card purchases

Requested features

3 requests
  • Improve search and location functionality
  • Enhance user experience and app stability
  • Provide better customer support channels

Terrestream

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

MileagePlus X

No in-app purchases

None

Terrestream

No in-app purchases

Questions

Is MileagePlus X free?
MileagePlus X is free to download, with no in-app purchases.
Is Terrestream free?
Terrestream is free to download, with no in-app purchases.
Which has better reviews, MileagePlus X or Terrestream?
Terrestream is rated higher. MileagePlus X averages 4.8 out of 5 from 21K ratings, while Terrestream averages 5.0 from 1 ratings.
Do MileagePlus X or Terrestream have ads?
Neither MileagePlus X nor Terrestream shows ads.
Which is updated more often, MileagePlus X or Terrestream?
MileagePlus X ships an update monthly, and Terrestream every 3 days. Most recently, MileagePlus X was updated on November 5, 2026 and Terrestream on October 30, 2026.

Other comparisons