# NHD vs PDI Mobile

The clearest difference is rating: NHD at 4.7 against PDI Mobile's 3.6. PDI Mobile's advantage is ads (none vs shown) and update cadence (every 9 days vs every 11 months). On price, ratings volume, 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.

NHD holds the better App Store score, 4.7 against 3.6. Both are backed by a comparable volume of ratings — 6 and 16 respectively.

NHD ships an update every 11 months, PDI Mobile every 9 days. The most recent releases landed on November 2, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | NHD | PDI Mobile |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (6 ratings)](https://appshunter.io/ios/app/nhd-ca/id1373343639/reviews)** | [3.6 (16 ratings)](https://appshunter.io/ios/app/pdi-mobile/id1506273581/reviews) |
| Number of ratings | 6 | **16** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 11 months | **Every 9 days** |
| Monetization | Ad-supported | **Free** |
| Size | 44 MB | 102 MB |
| Requires iOS | **14.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Sacramento County Office of Education](https://appshunter.io/developer/508064349) | [Political Data Inc.](https://appshunter.io/developer/553675636) |

## What reviewers say

### NHD

[App page](https://appshunter.io/ios/app/nhd-ca/id1373343639)

This app helps participants navigate and stay updated on the National History Day - California State Contest. Create a personalized schedule for student projects like exhibits, documentaries, and websites, and use built-in maps and agendas to explore the competition.

**Highlights:** Create custom event schedules, View student project details, Access contest maps, Check event agendas, Stay updated on contest news

**Features:** macOS Compatibility

**In-app purchases:** none


### PDI Mobile

[App page](https://appshunter.io/ios/app/pdi-mobile/id1506273581)

This business application enhances functionality for canvassing projects. It offers seamless integration with existing workflows, improving efficiency for users involved in political data collection and management.

**Highlights:** Enhanced canvassing functionality, Seamless integration, Improved workflow efficiency, Data management tools

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is NHD free?

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

### Is PDI Mobile free?

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

### Which has better reviews, NHD or PDI Mobile?

NHD is rated higher. NHD averages 4.7 out of 5 from 6 ratings, while PDI Mobile averages 3.6 from 16 ratings.

### Do NHD or PDI Mobile have ads?

NHD shows ads; PDI Mobile does not.

### Which is updated more often, NHD or PDI Mobile?

NHD ships an update every 11 months, and PDI Mobile every 9 days. Most recently, NHD was updated on November 2, 2026 and PDI Mobile on November 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.*