Comparison

Hummingbird Biofeedback vs Aster

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

Head to head
About

Hummingbird Biofeedback

Features
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Hummingbird Biofeedback reads the Bluetooth signal your heart-rate strap (Whoop, Polar H10, Garmin HRM, โ€ฆ) is already broadcasting and shows live HRV, beat by beat, on your screen. No server. No account. The strap you already own, finally fully visible โ€” alongside real-time biofeedback for humming, meditation, breathwork, or simply sitting still. Pick a humming pattern and a pitch target moves across the screen, you hum along, and three live readouts update underneath โ€” a real-time picture of what your nervous system is doing, not just one number. โ€” WHAT YOU WATCH, LIVE โ€” HRV 5-minute rolling rMSSD โ€” the same metric used across the HRV ecosystem. Different moment of the day than your nightly score, same math. RSA Vagal depth. Every breath stretches and releases your heart rate; RSA measures how big that swing is, in milliseconds. It's the amplitude of your breath's pull on your heart โ€” and slow, deep humming widens it. Watch it widen, breath by breath. COHERENCE Rhythm, on a 0โ€“100 scale. How clean and orderly that wave is. When your breath and heartbeat settle into one smooth oscillation, coherence climbs toward the resonance "zone" โ€” the difference between a flute holding one clear note and a radio stuck between stations. Why three and not one? HRV alone is jumpy, and during slow breathing it can even dip โ€” even as the rhythm underneath gets deeper (RSA) and cleaner (coherence). The extra two metrics catch what a single number misses, so you can watch a session take shape in real time instead of guessing. What does five minutes of slow humming do to these numbers right now? What about fifteen minutes of meditation? Hummingbird is the simplest answer. โ€” FIVE HUMMING PATTERNS โ€” UNWIND Slow descending hum, the most-studied pattern. DRIFT Long, narrowly-descending hum with a lullaby-shaped contour. ANCHOR A held, steady pitch at a slow cadence. RESONATE Pitch and pace near the cardiovascular resonance band (~6 BPM). EXPLORE Free-form humming โ€” no target, no prescribed cadence. โ€” PLUS STILLNESS โ€” Silent, mic-free biofeedback for any quiet practice โ€” meditation, yoga nidra, body scan, pre-sleep wind-down, post-stress reset. No pitch target, no prescribed cadence. A passive expanding ring paces ~5.5 breaths/minute if you want an anchor; ignore it and the session still captures HRV, RSA, and coherence either way. Pick a 5, 10, 15, 20, or 30-minute timer (or Open) and tag the session with what you actually did, so a 6-ms rMSSD rise after "Pre-sleep" and a 6-ms rise after "Cold plunge" stay sortable in your history. Tap the (i) on any card for the design rationale and references to the published research that informed each parameter (pitch contour, range, cycle timing, session length).

About

Aster

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You know your pain is real. Aster helps you prove it. People with endometriosis wait years for a diagnosis โ€” and those who feel dismissed by their doctors wait longest. What finally gets someone believed usually isn't a number. It's being able to say what the pain feels like, and what it stopped them doing. Aster records all three. HOW BAD, WHAT KIND, WHAT IT COST A 0โ€“10 scale for intensity. Pain character โ€” cramping, labour-like, burning, squeezing, stabbing, dragging, nerve-like. And how much the episode disrupted your day, from barely to couldn't get out of bed. LOG A FLARE IN SECONDS Built for your worst days: big tappable targets, one-tap symptom and location chips, no typing required. Log from the app, your Lock Screen, or a Home Screen widget. Choose which symptoms appear on your log screen so it stays fast. TRACK WHAT ACTUALLY HAPPENS TO YOU Twenty-three symptoms across thirteen pain locations. Cramps, bloating and endo belly, fatigue, brain fog, nausea, clotting, heavy bleeding, spotting, constipation and diarrhoea tracked separately, bladder urgency and leaking, pain with sex, headache, lightheadedness, mood changes and more โ€” across pelvic, abdominal, lower back, hip, thigh, leg and bowel locations. A REPORT DOCTORS TAKE SERIOUSLY Generate a clean one-page PDF designed around what a clinician needs: average and peak pain, flare days per month, your most frequent symptoms, how pain lines up with your cycle, what it's costing you day to day, and the treatments you've tried. Timestamped, structured, and hard to wave away. SEE YOUR PATTERNS Charts show pain over time, symptom frequency, and how symptoms line up with your cycle โ€” so you spot the patterns before your specialist asks. COMPLETELY PRIVATE No account. No cloud. No tracking. Everything stays on your device, protected by Face ID if you choose. We can't see your data โ€” we built it that way on purpose. FREE VS PREMIUM Logging, cycle tracking, reminders, basic trends and the basic doctor report are free โ€” forever. Premium ($3.99/month or $29.99/year, 1-month free trial) adds cycle-day and phase analysis, custom report ranges, medication effectiveness insights, appointment reminders and unlimited history export. Aster is a symptom record, not medical advice, and it doesn't diagnose anything โ€” only a clinician can do that. Your pain deserves to be on the record, and taken seriously. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Hummingbird Biofeedback4 screens
Aster4 screens

Verdict

The call

The clearest difference is device support: Hummingbird Biofeedback at 3 against Aster's 1. Hummingbird Biofeedback also leads on iOS requirement (15.1 vs 17.0). On price, update cadence, ads and in-app purchases there is nothing between them.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Hummingbird Biofeedback sells 1 one-off in-app purchase and Aster sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Hummingbird Biofeedback ships an update monthly, Aster every 3 weeks. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.

Scorecard2 real differences ยท 4 level
Hummingbird Biofeedback versus Aster: the parameters behind the verdict, then further details
ParameterHummingbird BiofeedbackAster
PriceFreeFree
Update frequencyMonthlyEvery 3 weeks โ€” better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, iPod โ€” betteriPhone
Requires iOS15.1 โ€” better17.0
Further details โ€” not scored
Size25 MB2 MB
Age rating4+12+
DeveloperSamantha ChanGradatim Pty Ltd

In-app purchases

1 purchases

Hummingbird Biofeedback

One-time1
  • Hummingbird Biofeedback$29.99
2 purchases

Aster

Subscriptions2
  • Aster Premium Monthly7 Days trial$3.991 Month
  • Aster Premium Yearly7 Days trial$29.991 Year

Questions

Is Hummingbird Biofeedback free?
Hummingbird Biofeedback is free to download, with in-app purchases available.
Is Aster free?
Aster is free to download, with in-app purchases available.
Do Hummingbird Biofeedback or Aster have ads?
Neither Hummingbird Biofeedback nor Aster shows ads.
Which is updated more often, Hummingbird Biofeedback or Aster?
Hummingbird Biofeedback ships an update monthly, and Aster every 3 weeks. Most recently, Hummingbird Biofeedback was updated on October 28, 2026 and Aster on October 24, 2026.

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