# Castor Connect vs Solanx

The clearest difference is update cadence: Solanx at every 2 weeks against Castor Connect's every 2 months. Castor Connect's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Castor Connect ships an update every 2 months, Solanx every 2 weeks. The most recent releases landed on October 25, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Castor Connect | Solanx |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Free | — |
| Size | 28 MB | 25 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Ciwit B.V.](https://appshunter.io/developer/1009756772) | [BISIL](https://appshunter.io/developer/1003721446) |

## What reviewers say

### Castor Connect

[App page](https://appshunter.io/ios/app/castor-connect/id1532340302)

This app allows study participants to securely complete electronic patient-reported outcome (ePRO) questionnaires on their mobile devices. It offers offline data storage and manual syncing for flexibility. Access requires an invitation or activation code.

**Highlights:** ePRO questionnaire completion, Offline data storage, Manual data sync, Secure participant data, Native mobile application

**In-app purchases:** none


### Solanx

[App page](https://appshunter.io/ios/app/solanx/id6791511661)

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

**In-app purchases:** none


## Frequently asked questions

### Is Castor Connect free?

Castor Connect is free to download, with no in-app purchases.

### Is Solanx free?

Solanx is free to download, with no in-app purchases.

### Do Castor Connect or Solanx have ads?

Neither Castor Connect nor Solanx shows ads.

### Which is updated more often, Castor Connect or Solanx?

Castor Connect ships an update every 2 months, and Solanx every 2 weeks. Most recently, Castor Connect was updated on October 25, 2026 and Solanx on October 9, 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.*