# PSIS vs PSIS4

The clearest difference is update cadence: PSIS at every 3 weeks against PSIS4's every 20 months. PSIS also leads on device support. On price, in-app purchases and iOS requirement there is nothing between them.

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

PSIS ships an update every 3 weeks, PSIS4 every 20 months. The most recent releases landed on September 9, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | PSIS | PSIS4 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.3 (7 ratings)](https://appshunter.io/ios/app/psis-bsl/id1503868212/reviews)** | — |
| Number of ratings | **7** | — |
| In-app purchases | No | No |
| Ads | No | — |
| Update frequency | **Every 3 weeks** | Every 20 months |
| Monetization | Free | — |
| Size | 77 MB | 30 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | **iPhone, iPad, iPod** | — |
| Age rating | 4+ | 4+ |
| Developer | [Paññāsāstra University of Cambodia](https://appshunter.io/developer/1474826859) | [YONG SOKHENG](https://appshunter.io/developer/1702023342) |

## What reviewers say

### PSIS

[App page](https://appshunter.io/ios/app/psis-bsl/id1503868212)

This educational app provides students, parents, and lecturers with tools for managing class schedules, accessing digital materials, and tracking academic progress. Students can submit assignments and communicate with lecturers, while parents receive notifications and can view tuition fees.

**Highlights:** Class schedule management, Digital lessons and materials, Attendance and performance tracking, Assignment submission, Student-lecturer communication, Parental notifications and fee tracking

**Features:** Vision Pro support

**In-app purchases:** none


### PSIS4

[App page](https://appshunter.io/ios/app/psis4/id6460007747)

**In-app purchases:** none


## Frequently asked questions

### Is PSIS free?

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

### Is PSIS4 free?

PSIS4 is free to download, with no in-app purchases.

### Which is updated more often, PSIS or PSIS4?

PSIS ships an update every 3 weeks, and PSIS4 every 20 months. Most recently, PSIS was updated on September 9, 2026 and PSIS4 on September 7, 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.*