Comparison

e vs StandbyCalc

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

Head to head

UK alarm battery sizing tool

Free

🔧 Utilities

No ratingsView app →

About

e

Features

Read full description

We work thinking on you! Our objective, to make things easier and this app helps you to configure e-connect board in a few steps.

About

StandbyCalc

Features

Read full description

StandbyCalc is the fastest way to calculate standby battery requirements for UK fire and intruder alarm systems. Built for engineers, by engineers. Enter your quiescent and alarm currents, select your system grade or category, and get an instant answer — including which standard battery size you need. SUPPORTS: - Intruder alarms — BS EN 50131 / BS 9263, Grades 1-4 - Fire alarms — BS 5839-1:2025, Categories L, M, and P - Standalone PSUs — custom standby and alarm periods FREE FEATURES: - All battery calculations - All standards and grades - Save unlimited calculations - Standard battery size recommendations PRO UPGRADE (one-time purchase): - iCloud backup across devices - PDF reports with full formula working - Add your company logo and branding - Share reports via email, AirDrop, or Files - Professional compliance documentation Compliant with NSI and SSAIB requirements. Calculations per BS 9263 Annex C and BS 5839-1:2025 Annexe E. No account required. No subscription. Just open and calculate.

Screenshots

e4 screens

StandbyCalc4 screens

Verdict

The call

The clearest difference is in-app purchases: e at none against StandbyCalc's 1. e also leads on ads (none vs shown) and iOS requirement (9.0 vs 17.0). StandbyCalc's advantage is update cadence (every 4 months vs every 16 months). On price 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. StandbyCalc sells 1 one-off in-app purchase. e asks for nothing beyond the download.

UpkeepUpdate frequency

e ships an update every 16 months, StandbyCalc every 4 months. The most recent releases landed on September 29, 2026 and October 15, 2026 respectively.

Scorecard4 real differences · 2 level

e versus StandbyCalc: the parameters behind the verdict, then further details
Parameter	e	StandbyCalc
Price	Free	Free
Update frequency	Every 16 months	Every 4 months — better
Ads	No — better	Yes
In-app purchases	No — better	Yes
Devices	iPhone, iPod	iPhone, iPad
Requires iOS	9.0 — better	17.0
Further details — not scored
Size	55 MB	4 MB
Age rating	4+	4+
Developer	Endepro Software, S.L.	D4N LTD

In-app purchases

None

e

No in-app purchases

1 purchases

StandbyCalc

One-time1

StandbyCalc Pro$9.99

Questions

Is e free?

e is free to download, with no in-app purchases.

Is StandbyCalc free?

StandbyCalc is free to download, with in-app purchases available.

Do e or StandbyCalc have ads?

StandbyCalc shows ads; e does not.

Which is updated more often, e or StandbyCalc?

e ships an update every 16 months, and StandbyCalc every 4 months. Most recently, e was updated on September 29, 2026 and StandbyCalc on October 15, 2026.