VPD Tool vs DomainDig
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VPD Tool
This utility app helps growers understand Vapor Pressure Deficit (VPD) for optimal plant growth. It features an interactive heatmap and stage presets to guide environmental adjustments. Calculations are performed on-device for privacy.
- Interactive VPD heatmap
- Stage-specific VPD ranges
- Leaf and Air VPD calculation
- Home and Lock Screen widgets
- On-device calculations
- CSV log export
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Know your VPD in seconds. Enter temperature & humidity (or tap the interactive heatmap) to see Leaf VPD and Air VPD with scientifically labeled isolines. Choose Seedling / Veg / Flower / Late Flowering to see target VPD ranges and how best to nudge your environment to “ideal.” Why growers love it • Interactive heatmap: drag to explore temperature–humidity combos • Stage presets: recommended VPD bands by plant development stage • Leaf vs Air: leaf–air offset, dew point, absolute humidity • Beautiful widgets: small/medium/large Home & Lock Screen widgets • Private by design: on-device calculations, no account required Details • VPD = es(T) × (1 − RH/100); leaf VPD uses leaf temperature (air + ΔT) • Absolute humidity via water vapor partial pressure (ideal gas law) • Full support for °C/°F, metric/imperial • Export logs to CSV Support Questions or feedback: support@nicksberryfarm.com
DomainDig
Inspect domains and servers with comprehensive diagnostics. Quickly check DNS records, SSL certificates, email security, HTTP headers, and network reachability. Includes IP geolocation and a history of your lookups.
- DNS record lookup (A, MX, NS, TXT, CNAME)
- SSL/TLS certificate inspection
- Email security record parsing (SPF, DMARC, DKIM)
- HTTP header analysis
- Redirect chain tracing
- Port scanning and latency measurement
- IP geolocation with map view
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DomainDig is a fast, no-frills domain inspection tool for developers, sysadmins, and anyone who manages or troubleshoots servers and infrastructure. Enter any domain and run a full diagnostic in seconds: DNS: query A, AAAA, MX, NS, TXT, CNAME, SOA, SRV, CAA, and DS records including wildcard entries, with TTL values, DNSSEC status, and reverse DNS (PTR) lookup for the resolved IP. SSL/TLS: inspect the full certificate chain — common name, SANs, issuer, validity dates, TLS version and cipher, and days until expiry with automatic color-coded warnings. Email Security: parse SPF, DMARC, DKIM, MTA-STS, and BIMI records with pass/fail indicators so you can verify email deliverability at a glance. HTTP Headers: fire a HEAD request and review all response headers, with security-relevant headers (HSTS, CSP, X-Frame-Options, and more) highlighted automatically. Redirect Chain: trace every HTTP redirect hop from initial request to final destination, with status codes at each step. Reachability & Ports: measure TCP latency on ports 80 and 443, and scan common ports (FTP, SSH, SMTP, MySQL, PostgreSQL, and more) to see what's open. IP Geolocation: look up the hosting org, city, region, and country for the resolved IP, with a live map view. Ownership & Subdomains: pull registrar, registration and expiry dates, and nameservers via RDAP, check domain availability, and discover subdomains. Every result loads in parallel and independently, then rolls up into a risk score with plain-language insights. Go beyond a single lookup: - Monitor domains on a schedule and get alerts when DNS, TLS, or email records change. - Group domains into Workflows and run them as a batch. - Compare any two domains side by side, and track changes across a full snapshot history. - Run structured Audit sessions with checklists, findings, and evidence. - Export as text, CSV, JSON, Markdown, or PDF — single reports or whole portfolios. - Home Screen widgets, Shortcuts, and a share extension put it where you work. - Optional iCloud sync keeps your domains and history across your devices. - A built-in local API exposes reports to your own scripts and automation. Local-first by design: your data stays on device unless you export, share, or sync it. No accounts. No ads. No tracking.
Screenshots
Verdict
The clearest difference is price: DomainDig at Free against VPD Tool's $0.49. DomainDig also leads on update cadence (every 2 weeks vs every 2 months) and ratings volume (3 vs 1). On rating, review sentiment, 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
DomainDig is free to download; VPD Tool costs $0.49 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for VPD Tool against 5.0 for DomainDig. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
VPD Tool ships an update every 2 months, DomainDig every 2 weeks. The most recent releases landed on October 18, 2026 and October 25, 2026 respectively.
| Parameter | VPD Tool | DomainDig |
|---|---|---|
| Price | $0.49 | Free — better |
| Rating | 5.0 (1 ratings) | 5.0 (3 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 1 | 3 — better |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.5 | 17.6 — better |
| Further details — not scored | ||
| Size | 2 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | Nicholas Hwang | Christian Cleberg |
Customer experience
VPD Tool
DomainDig
In-app purchases
VPD Tool
No in-app purchases
DomainDig
No in-app purchases









