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Four To Twenty: mA/V Converter vs its rivals

Side-by-side comparison against Four To Twenty: mA/V Converter's closest competitors — identity, store metrics, ratings & sentiment, and strategic intel.

Four To Twenty: mA/V Converter
This App
Engineers Toolbox
Nemesis
Calculator #
Peer
PCalc
Peer
Electrical Calculations
Peer
Amperes 4- battery charge info
New Kid
Core Identity
DeveloperJon GiambattistaCharles CrawfordIncpt.MobisTLA Systems Ltd.Egal Net di Ettore GallinaCrioSoft LLC
CategoryUtilitiesReferenceUtilitiesUtilitiesProductivityUtilities
PlatformiOSiOS, AndroidiOS, AndroidiOS, AndroidiOS, AndroidiOS, Android
Store Metrics
Rating4.5 / 51.0 / 54.6 / 54.7 / 54.6 / 54.4 / 5
Ratings Count10135,622762124638
PriceUSD0.99FreeFree$9.99Free$2.99
Release DateOct 30, 2017Jul 31, 2023Aug 31, 2011Feb 8, 2019Jun 6, 2015Jul 2, 2017
Last UpdatedOct 9, 2020Jul 31, 2023Mar 12, 2026Mar 12, 2026Mar 3, 2026Mar 24, 2026
Sentiment & Reviews
Sentimentpositive-negative--positive
Score80/100-35/100--82/100
Praises
  • The application provides a straightforward and accessible experience for users performing basic mathematical calculations
-
  • Simple and accurate calculation logic provides reliable utility for everyday math tasks
--
  • Simple and accurate battery monitoring provides clear visibility into charging speeds and health metrics
Complaints--
  • Aggressive full-screen advertisements interrupt core functionality and degrade the user experience
--
  • Inaccurate charging status reporting causes confusion when using non-standard or vehicle-based power sources
Requests
  • Users request the inclusion of mathematical formulas to explain the logic behind the calculated results
  • Adding percentage-based range values would help users interpret data within specific input boundaries
-
  • Integration of unit and currency conversion tools to match stock calculator capabilities
--
  • Integration of battery status indicators into the native system status bar for better visibility
Strategic Intel
Strengths
  • Simple interface reduces cognitive load for field technicians
  • 8 visual themes provide aesthetic differentiation in a utilitarian category
-
  • Mathematical display engine functions as a brand moat by increasing academic switching costs
  • History tape retention loop reduces friction for repetitive multi-step calculations
--
  • Proprietary global benchmarking database creates switching costs [Market Segment]
  • Specialized mA measurement provides diagnostic precision [Feature Set]
Weaknesses
  • $0.99 price point creates a barrier against free, comprehensive engineering suites
  • Lack of formula transparency limits professional trust
-
  • Aggressive full-screen ad frequency drives high churn among core utility users
  • Recent UI regressions removed essential quick-answer displays, alienating long-term power users
--
  • iOS price point at $2.99 above category median [Pricing]
  • Hardware-specific measurement failures on Samsung devices [Compatibility]
Pricingpaidfreefreemiumfreefreemiumfreemium
Momentum--MaintenanceIntenseActiveMaintenance
Update Cadence--5 versions, 5 majors/6mo, ~144d avg5 versions5 versions5 versions, 3 majors/6mo, ~135d avg

Compare Four To Twenty: mA/V Converter head-to-head

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AI-powered analysis with editorial review, built from publicly available sources. Marlvel.ai is not affiliated with, endorsed by, or sponsored by Four To Twenty: mA/V Converter, its developer, the app publisher, Apple, or Google Play. All trademarks, logos, and screenshots referenced remain the property of their respective owners.

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