Comparison

Theta vs BellAlert

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

Head to head
About

Theta

Read full description

Theta-Meter X Theta-Meter X is a companion application designed to work with compatible Theta-Meter hardware devices.  The app connects via Bluetooth Low Energy (BLE 4.0 or higher) or Wi-Fi and displays real-time electrical resistance  measurements from objects connected to the device’s electrodes. Key Features: - Real-time visualization of electrical resistance changes - Clear analog-style needle indicator for dynamic monitoring - Bluetooth LE and Wi-Fi connectivity - Simple, user-friendly interface - Stable data transmission from supported hardware devices How It Works When connected to a compatible device, the app measures and displays variations in electrical resistance detected between  attached electrodes. The needle indicator provides a continuous visual representation of resistance fluctuations, allowing  users to observe dynamic changes over time. Intended Use Theta-Meter X is designed for general experimental, educational, and technical purposes involving electrical resistance measurement.  It is intended for use with compatible hardware devices only. Important Notice This application and the associated hardware are not medical devices. They are not intended for diagnosing, treating, curing,  preventing, or mitigating any disease or health condition. The app does not provide medical, therapeutic, or psychological advice.

About

BellAlert

Assign custom sounds to notifications to instantly know what's happening without looking at your phone. Share unique alert codes with others to send them instant, personalized notifications with their chosen sounds. Manage alerts with timestamps, disappearing notifications, and an "oops" feature to un-ring alerts.

Highlights
  • Custom sounds for each notification
  • Shareable alert codes
  • Instant alerts on recipient devices
  • Home Screen widget for quick alerts
  • Undo/cancel sent alerts
  • Disappearing notifications
  • Private and track-free design
Features
Read full description

Some notifications matter more than others. Bell Alerts lets you give each one its own sound — so you know what just happened without even looking at your phone. Create a bell, share its code, and ring it. Everyone you've shared it with gets the alert instantly — each on their own phone, with the sound they picked. Dinner's ready, the dog's at the door, the meeting's starting: make it a bell. MAKE IT YOURS • A different sound for every bell — a dozen original tones to choose from • Per phone: you pick your sound, your family picks theirs • Vibrate-only or mute any bell, anytime • 11 app icons to match your style SEND A BELL IN A TAP • Create a bell — it gets its own private, unguessable code • Share the code; anyone who adds it is subscribed • Ring it from the app — or straight from a Home Screen widget, without opening anything • Changed your mind? "Oops" un-rings it — the alert crosses itself out everywhere STAY ON TOP OF IT • Recent rings at a glance, with timestamps — canceled ones clearly marked • A Home Screen widget shows the latest bells the moment they ring • Disappearing alerts tidy themselves up after a time you set PRIVATE BY DESIGN • No account, no sign-up, no tracking • Bells are private codes — only the people you share them with get the rings • Verified on device with App Check; standard encryption only FOR POWER USERS Bell Alerts can also receive alerts from your own internet server — the same bring-your-own-server idea as the open-source app ntfy. Send a notification from any script or service you run and it arrives as a custom bell on every subscribed phone. It's a software integration over the internet; no extra hardware or accessory is involved. Setup guide included. Make every alert sound like what it is.

Screenshots

Theta2 screens
BellAlert4 screens

Verdict

The call

The clearest difference is update cadence: BellAlert at every 2 days against Theta's every 3 months. On price, ads, in-app purchases and device support 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.

UpkeepUpdate frequency

Theta ships an update every 3 months, BellAlert every 2 days. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

Scorecard1 real difference · 9 level
Theta versus BellAlert: the parameters behind the verdict, then further details
ParameterThetaBellAlert
PriceFreeFree
Rating—4.9 (12 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—12 — better
Update frequencyEvery 3 monthsEvery 2 days — better
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPad, Mac — betteriPhone, iPad
Requires iOS1716.0 — better
Further details — not scored
Size18 MB35 MB
Age rating12+4+
DeveloperMikhail FedorovCurtis Waldner

In-app purchases

None

Theta

No in-app purchases

None

BellAlert

No in-app purchases

Questions

Is Theta free?
Theta is free to download, with no in-app purchases.
Is BellAlert free?
BellAlert is free to download, with no in-app purchases.
Do Theta or BellAlert have ads?
Neither Theta nor BellAlert shows ads.
Which is updated more often, Theta or BellAlert?
Theta ships an update every 3 months, and BellAlert every 2 days. Most recently, Theta was updated on October 29, 2026 and BellAlert on October 24, 2026.

Other comparisons