Acidity vs echo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Acidity
This utility extension for Safari provides quick access to archived versions of web pages. It allows users to manually navigate to archives or set up automatic redirection based on custom regex patterns.
- Access archived page versions
- Toolbar action for quick access
- Regex matching for automatic navigation
- Safari extension
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Acidity is a Safari extension for navigating to archived versions of pages. Quickly access page archives through a button in the toolbar. Specify regex matches to automatically redirect certain sites to archives.
echo
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Echo is notes at the speed of a text. Open, type, send. Make quick lists. Sketch ideas. Use hashtags to organize. Start threads to group thoughts. Pin important notes. Search is instant. Sync across devices. Private by default. Minimal by design.
Screenshots
Verdict
The clearest difference is price: Acidity at Free against echo's $2.99. Acidity also leads on device support (4 vs 1) and iOS requirement (15.0 vs 26.0). echo's advantage is update cadence (every 3 days vs every 4 months). On ads and in-app purchases 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
Acidity is free to download; echo costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Acidity ships an update every 4 months, echo every 3 days. The most recent releases landed on October 8, 2026 and October 26, 2026 respectively.
| Parameter | Acidity | echo |
|---|---|---|
| Price | Free — better | $2.99 |
| Rating | 4.2 (10 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 10 — better | — |
| Update frequency | Every 4 months | Every 3 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone |
| Requires iOS | 15.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 8 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Octalwise | Arjun Mahanti |
In-app purchases
Acidity
No in-app purchases
echo
No in-app purchases
