# TallyFlex vs Kestrel ABA

The clearest difference is device support: TallyFlex at 3 against Kestrel ABA's 1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. TallyFlex sells 2 in-app purchases, starting at $27.99 per month and Kestrel ABA sells 1 in-app purchase, starting at $14.99 per month. Whichever you choose, the download price is not the number that matters.

TallyFlex ships an update every 10 days, Kestrel ABA every 6 days. The most recent releases landed on October 12, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | TallyFlex | Kestrel ABA |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (87 ratings)](https://appshunter.io/ios/app/tallyflex-aba-data-collection/id1531412972/reviews)** | — |
| Number of ratings | **87** | — |
| Positive reviews | 64.1% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | **Every 6 days** |
| Monetization | Free with in-app purchases | — |
| Size | 87 MB | 64 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [TallyFlex LLC](https://appshunter.io/developer/1531412974) | [Nathan Simmons](https://appshunter.io/developer/1850002641) |

## What reviewers say

### TallyFlex

[App page](https://appshunter.io/ios/app/tallyflex-aba-data-collection/id1531412972)

This app replaces paper data sheets for behavioral data collection. It helps professionals like BCBAs and RBTs work faster and more accurately with clients in clinics, schools, and homes. It offers various tracking methods and secure data export for reports.

**Highlights:** Replace paper data sheets, Track ABC data, frequency, duration, latency, Automatic timers for interval recording, Task analysis and prompt codes, Track multiple behaviors simultaneously, Export data to PDF, CSV, XLSX, Works offline

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| TallyFlex Solo Monthly | $27.99 | per month |
| Solo Yearly | $279.99 | per year |

**What reviewers like**

- 👍 Easy to use and user-friendly
- 🚀 Quick data collection
- 📊 Visual reports and data tracking
- 💡 Customizable behavior tracking
- ✅ Great for RBTs and BCBAs

**What reviewers complain about**

- 💰 Subscription model disliked
- 📉 Data export challenges
- 🐛 Calculation glitches
- 🤔 Lack of clear documentation/help
- 🚫 Inability to add/manage students (free version)

**Reported bugs**

- Calendar not showing current sessions
- Data export results in empty Excel sheet
- Calculations and percentages are unreliable
- Data stops being counted after a certain number of opportunities
- Exported data format for duration is hard to graph

**Requested features**

- Offer a 'lite' subscription for SLPAs/BCaBAs
- Add more data collection options/types (chaining, TAs, checklists)
- Allow uploading pre-made data sheets
- Add sound alerts for timers
- Ability to re-organize behaviors on screens


### Kestrel ABA

[App page](https://appshunter.io/ios/app/kestrel-aba/id6793233786)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Kestrel Pro | $14.99 | per month |


## Frequently asked questions

### Is TallyFlex free?

TallyFlex is free to download, with in-app purchases available.

### Is Kestrel ABA free?

Kestrel ABA is free to download, with in-app purchases available.

### Do TallyFlex or Kestrel ABA have ads?

Neither TallyFlex nor Kestrel ABA shows ads.

### Which is updated more often, TallyFlex or Kestrel ABA?

TallyFlex ships an update every 10 days, and Kestrel ABA every 6 days. Most recently, TallyFlex was updated on October 12, 2026 and Kestrel ABA on September 25, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*