Comparison

eCall Pro vs SI Calculator Pro

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

Head to head

LSI / RSI Calculator

About

eCall Pro

Read full description

TOUCHLESS DISPATCH Call an elevator cab for dispatch to a destination from your iOS device without touching anything outside or inside the cab! Receive an elevator assignment on your phone once the call is made.

About

SI Calculator Pro

Read full description

PLEASE NOTE THAT THIS APP IS INTENDED FOR SCL CUSTOMERS ONLY AND WILL REQUIRE YOU TO MAKE AN ACCOUNT TO USE THIS APP. Take the guess work out of your water chemistry by using SI Calculator Pro to get your desired water chemistry. This App is a Saturation Index Calculator that will give you your LSI and RSI values. Simply input your waters current chemistry values then tweak the Hardness and Alkalinity Fields in the desired column to get the perfect water chemistry. SI Calculator Pro can predict the values of the pH and Conductivity after adjusting the Hardness and Alkalinity fields. SI Calculator Pro adds more functionality compared to our original SI Calculator app. Hardness, Alkalinity, Cyanuric Acid and Chlorine calculators have all been added to SI Calculator Pro.

Screenshots

eCall Pro3 screens

SI Calculator Pro4 screens

Verdict

The call

The clearest difference is update cadence: eCall Pro at every 3 months against SI Calculator Pro's every 10 months. SI Calculator Pro's advantage is device support (3 vs 1) and iOS requirement (12.4 vs 16.0). On price 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

eCall Pro ships an update every 3 months, SI Calculator Pro every 10 months. The most recent releases landed on October 16, 2026 and October 27, 2026 respectively.

Scorecard3 real differences · 3 level

eCall Pro versus SI Calculator Pro: the parameters behind the verdict, then further details
Parameter	eCall Pro	SI Calculator Pro
Price	Free	Free
Update frequency	Every 3 months — better	Every 10 months
Ads	No	—
In-app purchases	No	No
Devices	iPhone	iPhone, iPad, iPod — better
Requires iOS	16.0	12.4 — better
Further details — not scored
Size	9 MB	15 MB
Age rating	4+	4+
Developer	Otis Elevator Company	Select Chemicals Limited

In-app purchases

None

eCall Pro

No in-app purchases

None

SI Calculator Pro

No in-app purchases

Questions

Is eCall Pro free?

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

Is SI Calculator Pro free?

SI Calculator Pro is free to download, with no in-app purchases.

Which is updated more often, eCall Pro or SI Calculator Pro?

eCall Pro ships an update every 3 months, and SI Calculator Pro every 10 months. Most recently, eCall Pro was updated on October 16, 2026 and SI Calculator Pro on October 27, 2026.