# Solis vs 21a OBMEP

The clearest difference is update cadence: 21a OBMEP at every 4 days against Solis's every 2 months. 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.

Solis ships an update every 2 months, 21a OBMEP every 4 days. The most recent releases landed on October 3, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Solis | 21a OBMEP |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | — | Free |
| Size | 27 MB | 21 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Inca Tecnologia de Produtos e Servicos Ltda.](https://appshunter.io/developer/1701851995) | [Instituto de Matematica Pura e Aplicada](https://appshunter.io/developer/1626544658) |

## What reviewers say

### Solis

[App page](https://appshunter.io/ios/app/solis/id6459536732)

**Features:** macOS Compatibility

**In-app purchases:** none


### 21a OBMEP

[App page](https://appshunter.io/ios/app/21a-obmep/id6744337826)

This app allows school administrators to digitize and submit student answer sheets for a math competition. It also facilitates the completion of administrative forms related to the competition.

**Highlights:** Digitize answer sheets, Submit student responses, Fill out administrative forms, Digital submission of answer cards, Complete RAIG and Shipping Document

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

**In-app purchases:** none


## Frequently asked questions

### Is Solis free?

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

### Is 21a OBMEP free?

21a OBMEP is free to download, with no in-app purchases.

### Do Solis or 21a OBMEP have ads?

Neither Solis nor 21a OBMEP shows ads.

### Which is updated more often, Solis or 21a OBMEP?

Solis ships an update every 2 months, and 21a OBMEP every 4 days. Most recently, Solis was updated on October 3, 2026 and 21a OBMEP on October 10, 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.*