Comparison

Synology Drive vs VoltBook

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Synology Drive

Access and manage files stored on your Synology NAS from your mobile device. This app allows you to view various file types, including office documents, and offers convenient file management features like syncing, searching, and sharing on the go.

Highlights
  • Access Synology NAS files on the go
  • View documents, spreadsheets, and slides
  • Sync files
  • Search files
  • Share files
  • Move and label files
Features
Read full description

**To use this app and enjoy its features, you must own Synology NAS and install the latest Synology Drive Server.** Synology Drive iOS mobile app allows you to easily access and manage files in your Synology Drive on the go. In addition to common file types, such as documents, images, videos, and music, the app's user-friendly in-app viewer can open Synology Office documents, spreadsheets, and slides. Convenient management features, such as syncing, searching, sharing, moving, and applying labels to files, are all available in the app, allowing users to complete tasks efficiently anytime, anywhere.

About

VoltBook

This app provides electricians with a comprehensive digital toolbox, featuring numerous electrical calculators, searchable code references, and job documentation tools. It offers offline functionality for all calculators and tables, with AI assistance for calculations and field notes.

Highlights
  • 75+ electrical calculators
  • Searchable NEC code references (2020, 2023, 2026)
  • Offline functionality
  • AI Assistant for calculations and notes
  • Nameplate Scanner for equipment data
  • Job documentation and material lists (Pro)
Features
Read full description

VoltBook is the electrician's field toolbox: fast, accurate electrical calculators, searchable code references, and job documentation — built for the panel room, the lift, and the trench. All 75 calculators and every table are free and work fully offline, forever — no account required. 75 CALCULATORS, 14 CATEGORIES • Electrical basics — Ohm's law, AC power, power factor, energy cost • Conductors — voltage drop, ampacity, temperature and fill derating • Raceway — conduit fill and minimum size, with a custom cable library • Conduit and tube bending — offsets, saddles, stubs, kicks, segment bends • Motors, transformers, and VFDs — FLC, kVA, OCPD, overloads, V/Hz • Grounding and OCPD — EGC, GEC, continuous loads, breaker sizing • Fault current, instrumentation loops, PLC scaling, and unit conversions Results show their NEC references, and you can switch between the 2020, 2023, and 2026 editions. Save any calculation to a project for later. REFERENCE, WITHOUT THE FLIPPING Ampacity, conduit fill, grounding, and motor tables in a searchable format, plus a full electrical symbol library and step-by-step bending guides. AI THAT KNOWS THE TRADE Every plan includes AI requests each month — no account, key, or setup needed. Describe the job in plain language and the AI Assistant runs the verified calculators for you. Ask AI on any calculator to explain results or draft field notes, and use the Nameplate Scanner to pull data straight off motor, transformer, and VFD nameplates. VOLTBOOK PRO The calculators stay free forever. Pro unlocks the documentation workflow: • Unlimited projects and saved calculations • Material lists you can check off at the counter and send by text or email • Branded PDF calculation sheets and photo field reports • 500 AI requests a month (Free includes 5) • Bring your own OpenAI, Anthropic, Gemini, or OpenRouter API key for unlimited AI — usage billed by your provider, and your key never leaves your device Pro is available as a monthly or annual subscription. Payment is charged to your Apple ID, and subscriptions renew automatically unless canceled at least 24 hours before the end of the period. Manage or cancel anytime in your App Store settings. VoltBook is a professional aid — always verify results against the applicable code and local amendments before installation. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://voltbook.app/Home/Privacy

Screenshots

Synology Drive4 screens
VoltBook4 screens

Verdict

The call

The clearest difference is review sentiment: VoltBook at 100% against Synology Drive's 33%. VoltBook also leads on rating (5.0 vs 4.5) and update cadence (every 4 days vs every 3 months). Synology Drive's advantage is in-app purchases (none vs 2) and ratings volume (4.4K vs 1). On price, ads and device support 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. VoltBook sells 2 in-app purchases, starting at $4.99 per month. Synology Drive asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

VoltBook holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Synology Drive has 4.4K ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 33% of Synology Drive's written reviews are positive against 100% of VoltBook's.

UpkeepUpdate frequency

Synology Drive ships an update every 3 months, VoltBook every 4 days. The most recent releases landed on October 27, 2026 and October 8, 2026 respectively.

Scorecard7 real differences · 3 level
Synology Drive versus VoltBook: the parameters behind the verdict, then further details
ParameterSynology DriveVoltBook
PriceFreeFree
Rating4.5 (4.4K ratings)5.0 (1 ratings) — better
Positive reviews33.3% of reviews100.0% of reviews — better
Number of ratings4.4K — better1
Update frequencyEvery 3 monthsEvery 4 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFreemium
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.015.1 — better
Further details — not scored
Size279 MB60 MB
Age rating4+17+
DeveloperSynology Inc.Edward Anthony Whitfield

Customer experience

Synology Drive

All ratings4,371 ratings
Positive87.7%
Neutral3.5%
Negative8.7%
Written reviews795 reviews
Positive33.3%
Neutral17.9%
Negative48.8%

VoltBook

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Synology Drive

Reported bugs

5 issues
  • Unable to log in with 2FA
  • Sync tasks get stuck or fail
  • Folders not showing content
  • Incompatibility with latest iOS versions
  • Duplicated files and folders after sync

Requested features

5 requests
  • Add support for offline folder sync
  • Improve integration with iOS Files app
  • Implement document editing capabilities
  • Add option to customize file/folder naming
  • Enhance audio/video playback features

VoltBook

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Synology Drive

No in-app purchases

2 purchases

VoltBook

Subscriptions2
  • Pro Monthly$4.991 Month
  • Pro Annual$39.991 Year

Questions

Is Synology Drive free?
Synology Drive is free to download, with no in-app purchases.
Is VoltBook free?
VoltBook is free to download, with in-app purchases available.
Which has better reviews, Synology Drive or VoltBook?
VoltBook is rated higher. Synology Drive averages 4.5 out of 5 from 4.4K ratings, while VoltBook averages 5.0 from 1 ratings.
Do Synology Drive or VoltBook have ads?
Neither Synology Drive nor VoltBook shows ads.
Which is updated more often, Synology Drive or VoltBook?
Synology Drive ships an update every 3 months, and VoltBook every 4 days. Most recently, Synology Drive was updated on October 27, 2026 and VoltBook on October 8, 2026.

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