Quartzy vs Acid Interval
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Quartzy
Manage your lab's inventory with this mobile tool. Track stock, submit requests, and scan items to ensure supplies are always available, preventing experimental delays. Generate unique barcodes directly from your account.
- Track inventory in real-time
- Submit supply requests
- Scan and receive items
- Print unique barcodes
- Up-to-date stock view
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Quartzy Mobile App allows everyone in the lab to track inventory, creating a more up-to-date view of what is available in your lab, so supplies can be ordered in time and no experiment is delayed. Track and update inventory Submit supply requests Scan and receive items into inventory Print unique barcodes right from your Quartzy account
Acid Interval
This focus timer offers a visually unique approach to deep work, moving away from traditional interfaces. It provides customizable timers and engaging visual feedback to help users stay on task, even with the screen off. The app prioritizes a distraction-free experience with no account or data syncing required.
- Unique visual interface
- Customizable timer intervals
- Engaging animation mechanisms
- Screen-off notifications
- No account or data sync
- Phone lock compatibility
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A focus timer worth looking at. Most focus timers look like a spreadsheet with a countdown in it. This one is built the other way round. A single enormous numeral, bleeding off the edge of a field of acid green. Behind it, a mechanism that moves in time with the clock and never drifts. Rings that bounce, breathe, ripple inward, or pass momentum down a Newton's cradle. A square whose perimeter burns like a fuse, four seconds a side, for box breathing. When you start a session the whole field inverts to black and the numbers light up like something switched on behind them. Tap anywhere to start. Swipe to change the color. You never have to open a menu. 25/5, 50/10, 90/20, or count up. The classic pomodoro, longer ultradian blocks, or open-ended flow when you don't want a deadline. Timed properly. Built on timestamps, not ticks. Lock your phone, switch apps, come back: it is exactly where it should be. It tells you when you are done, even with the screen off. No account. No sync. No data leaves your phone. ACID INTERVAL PRO One payment unlocks all eight mechanisms, all ten colorways, and custom interval lengths. The timer itself is free and always will be.
Screenshots
Verdict
The clearest difference is rating: Acid Interval at 5.0 against Quartzy's 3.2. Quartzy's advantage is in-app purchases (none vs 1) and ratings volume (17 vs 1). On price, update cadence and ads 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. Acid Interval sells 1 one-off in-app purchase. Quartzy asks for nothing beyond the download.
Acid Interval holds the better App Store score, 5.0 against 3.2. That said, the two scores are not equally well evidenced: Quartzy has 17 ratings behind it against 1, so its average is the more settled of the two.
Quartzy ships an update monthly, Acid Interval every 2 weeks. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.
| Parameter | Quartzy | Acid Interval |
|---|---|---|
| Price | Free | Free |
| Rating | 3.2 (17 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 25.0% of reviews | — |
| Number of ratings | 17 — better | 1 |
| Update frequency | Monthly | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Ad-supported — better | Freemium |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.1 — better | 17.0 |
| Further details — not scored | ||
| Size | 39 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Quartzy, Inc. | Preston Carr |
Customer experience
Quartzy
Acid Interval
In-app purchases
Quartzy
No in-app purchases
Acid Interval
- Acid Interval Pro$2.99









