Castle vs WattShift
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Castle
Manage all your home expenses, from utility bills to renovation costs, in one secure app. It helps you track spending, find savings opportunities, and provides expert support for your home finance needs.
- Digital home records filing cabinet
- Consolidated bill payment
- Transaction monitoring for savings
- Fraud monitoring and security
- Expert home finance support
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Castle is the finance app that helps homeowners save time and money on their homes. When you use Castle to manage your home expenses — including utility payments, property and school taxes, renovation projects, and maintenance costs — you get: • A digital filing cabinet for all your home records; • Powerful bill-pay features to consolidate all of your household bills and auto-pays in one place; • Advanced transaction monitoring to identify tax credits, rebates, and other savings opportunities based on your spend; • Enhanced fraud monitoring and security features; • A dedicated team of experts on call to answer all your home finance questions and needs. With Castle, know where your money goes, pay in the most secure way, and optimize your investment in your home.
WattShift
This app intelligently manages your home thermostat to prioritize the use of renewable energy sources like solar and wind. It automatically shifts cooling and heating schedules to times when energy is cleaner and cheaper, potentially reducing your electricity bill by up to 30% without compromising comfort.
- Maximizes solar and wind energy use
- Reduces electricity bills up to 30%
- Maintains full comfort and temperature control
- Syncs with smart home devices
- Automatically shifts thermostat usage
- Prioritizes cleaner energy sources
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WattShift ensures your thermostat uses the cleanest energy possible while also keeping stable and potentially greatly decreasing your energy bill! Benefits: 1) Cleanest energy possible! Maximizes your use of solar and wind energy, minimizing fossil fuel-sourced electricity. 2) You save up to 30% on your electricity bill! 3) You maintain full comfort and control over the temperature in your home at all times! WattShift is an easy-to-use app that syncs with your smart home, cooling your home at cheaper times while still keeping the comfort you love. It manages your home by automatically shifting thermostat usage to cheaper times when the energy is cleaner, saving you money without sacrificing comfort or temperature control.
Screenshots
Verdict
The clearest difference is ratings volume: Castle at 5 against WattShift's 1. On price, rating, update cadence and ads 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for Castle against 5.0 for WattShift. That said, the two scores are not equally well evidenced: Castle has 5 ratings behind it against 1, so its average is the more settled of the two.
Castle ships an update monthly, WattShift every 3 weeks. Both last shipped on November 3, 2026.
| Parameter | Castle | WattShift |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (5 ratings) | 5.0 (1 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 5 — better | 1 |
| Update frequency | Monthly | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 15.1 — better | 16.0 |
| Further details — not scored | ||
| Size | 48 MB | 6 MB |
| Age rating | 17+ | 4+ |
| Developer | Castle Pay, Inc. | WattShift, Inc. |
Customer experience
Castle
WattShift
In-app purchases
Castle
No in-app purchases
WattShift
No in-app purchases









