GEMINI Pump System vs Custom Formulas
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
GEMINI Pump System
Monitor your sump pump system remotely. Check water levels, battery status, and pump operations. Features Local Link technology for offline connectivity.
- Remote water level check
- Battery health monitoring
- Pump status updates
- Local Link offline connectivity
- Wi-Fi restoration notification
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Introducing the GEMINI™ mobile app. Use it to remotely check your sump water level, battery health and charge, and pump state. If your Wi-Fi router goes out the innovative Local Link™ technology lets you check pump’s updates from the comfort of your bed, until Wi-Fi comes on when power is restored
Custom Formulas
This utility app allows users to create and manage complex calculations with multiple inputs and outputs. Formulas can be linked, grouped into categories, and customized for display precision. Share your custom calculations easily via email.
- Multiple input/output formula support
- Linked formulas via variable names
- Formula categorization
- Customizable variable display order
- Adjustable output decimal precision
- Email formula sharing
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This app is easy to use, but unlike simpler apps, multiple entered values can be fed into multiple formulas and multiple output values can be displayed. The output of one formula in a group can be fed into the next by using the same variable name. Related formulas can be grouped into categories to make them easy to find. e.g. Maths formulas, Surveying formulas, Loan interest formulas etc. The order of variables displayed to the user can be changed, as can the number of decimal digits of precision shown in the output fields. You can easily share formulas with other users of the app by emailing them. Three example formulas are pre-installed with the app. In order of increasing complexity they are: slope percentage, compound interest, and point scale factor.
Screenshots
Verdict
The clearest difference is review sentiment: Custom Formulas at 100% against GEMINI Pump System's 50%. Custom Formulas also leads on rating (5.0 vs 2.3) and update cadence (every 5 days vs every 43 months). GEMINI Pump System's advantage is price (Free vs $3.99) and ratings volume (3 vs 1). On ads, in-app purchases 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
GEMINI Pump System is free to download; Custom Formulas costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Custom Formulas holds the better App Store score, 5.0 against 2.3. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews point the same way: 50% of GEMINI Pump System's written reviews are positive against 100% of Custom Formulas's.
GEMINI Pump System ships an update every 43 months, Custom Formulas every 5 days. The most recent releases landed on September 19, 2026 and September 18, 2026 respectively.
| Parameter | GEMINI Pump System | Custom Formulas |
|---|---|---|
| Price | Free — better | $3.99 |
| Rating | 2.3 (3 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 50.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 3 — better | 1 |
| Update frequency | Every 43 months | Every 5 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.4 — better | 15.4 |
| Further details — not scored | ||
| Size | 10 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | WAYNE/SCOTT FETZER COMPANY | Anthony Dunk |
Customer experience
GEMINI Pump System
Custom Formulas
In-app purchases
GEMINI Pump System
No in-app purchases
Custom Formulas
No in-app purchases
Questions
Is GEMINI Pump System free?
Is Custom Formulas free?
Which has better reviews, GEMINI Pump System or Custom Formulas?
Do GEMINI Pump System or Custom Formulas have ads?
Which is updated more often, GEMINI Pump System or Custom Formulas?
Other comparisons
