Principle Mirror vs Digital Diaries
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Principle Mirror
Design interactive user interfaces with this companion app for a popular Mac design tool. Seamlessly open Principle files or mirror your Mac's design work directly to your device.
- Open Principle files
- Mirror Principle for Mac
- Interactive UI design
- Companion app functionality
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Principle Mirror is the companion app to Principle for Mac, a tool for designing interactive interfaces. Principle Mirror can open Principle files from other apps or mirror Principle for Mac when plugged in. “I just wanted to write to you quickly just to say — this. is. amazing. while I was watching the first tutorial I got tears in my eyes! seriously.” Hugo Ahlberg Designer, IDEO "This tool is amazing, very well done." Patrick Wong Designer, Lyft
Digital Diaries
This platform allows researchers to gain deep insights by immersing themselves in the lives of their respondents. Participants can complete activities, answer questions, and share media conveniently, even on the go. It facilitates exploration of emotions, behaviors, and contexts through interactive diaries and discussions.
- Activity-based market research
- Respondent immersion
- On-the-go participation
- Open and closed-ended questions
- Photo and video uploads
- Participant discussions
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Digital Diaries is an activity-based market research platform that enables researchers to immerse themselves in the lives of their respondents and research subjects. Research participants can engage in series of activities and respond to diaries and other questions whenever convenient for them, even while they are on the go. They can answer open-ended and closed-ended questions, upload photos and videos, and participate in discussions, which allow for researchers to explore emotions, behaviors, and contexts for deep insights. This mobile app works with the Digital Diaries web-based research platform and is not intended as a stand-alone product.
Screenshots
Verdict
The clearest difference is rating: Digital Diaries at 4.8 against Principle Mirror's 4.2. Digital Diaries also leads on review sentiment (67% vs 45%) and ratings volume (222 vs 14). Principle Mirror's advantage is iOS requirement (11.0 vs 16.0). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Digital Diaries holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: Digital Diaries has 222 ratings behind it against 14, so its average is the more settled of the two. Written reviews point the same way: 45% of Principle Mirror's written reviews are positive against 67% of Digital Diaries's.
Principle Mirror ships an update every 2 months, Digital Diaries every 5 weeks. Both last shipped on October 29, 2026.
| Parameter | Principle Mirror | Digital Diaries |
|---|---|---|
| Price | Free | Free |
| Rating | 4.2 (14 ratings) | 4.8 (222 ratings) — better |
| Positive reviews | 45.2% of reviews | 66.7% of reviews — better |
| Number of ratings | 14 | 222 — better |
| Update frequency | Every 2 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 11.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 1 MB | 94 MB |
| Age rating | 4+ | 4+ |
| Developer | Daniel Hooper | Forsta, Inc. |
Customer experience
Principle Mirror
Digital Diaries
In-app purchases
Principle Mirror
No in-app purchases
Digital Diaries
No in-app purchases
Questions
Is Principle Mirror free?
Is Digital Diaries free?
Which has better reviews, Principle Mirror or Digital Diaries?
Do Principle Mirror or Digital Diaries have ads?
Which is updated more often, Principle Mirror or Digital Diaries?
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