# Joining Forces vs Primal's 3D Knee

The clearest difference is in-app purchases: Joining Forces at none against Primal's 3D Knee's 1. Primal's 3D Knee's advantage is update cadence (every 2 months vs every 8 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Primal's 3D Knee sells 1 one-off in-app purchase. Joining Forces asks for nothing beyond the download.

Joining Forces ships an update every 8 months, Primal's 3D Knee every 2 months. The most recent releases landed on October 14, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Joining Forces | Primal's 3D Knee |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 71.4% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 16 MB | 125 MB |
| Requires iOS | 15.1 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [South Staffordshire and Shropshire Healthcare NHS Foundation Trust](https://appshunter.io/developer/626222949) | [Pharma Intelligence UK Ltd](https://appshunter.io/developer/1678054030) |

## What reviewers say

### Joining Forces

[App page](https://appshunter.io/ios/app/joining-forces/id626222866)

This app provides mental health resources and support for UK Armed Forces personnel, veterans, and their families. It connects users with information and services from the NHS and MOD Joint Medical Command.

**Highlights:** Mental health information, Support signposting, Resources for service personnel, Resources for veterans, Resources for families and friends, NHS and MOD integration

**Features:** macOS Compatibility

**In-app purchases:** none


### Primal's 3D Knee

[App page](https://appshunter.io/ios/app/primals-3d-knee/id1658547427)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Primal's 3D Knee | $39.99 | one-time |


## Frequently asked questions

### Is Joining Forces free?

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

### Is Primal's 3D Knee free?

Primal's 3D Knee is free to download, with in-app purchases available.

### Do Joining Forces or Primal's 3D Knee have ads?

Neither Joining Forces nor Primal's 3D Knee shows ads.

### Which is updated more often, Joining Forces or Primal's 3D Knee?

Joining Forces ships an update every 8 months, and Primal's 3D Knee every 2 months. Most recently, Joining Forces was updated on October 14, 2026 and Primal's 3D Knee on October 8, 2026.

---

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