Comparison

O3 vs Shift Calendar

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

Head to head
About

O3

Control your smart home environment with this app. Create custom profiles for different activities to manage HVAC, lighting, and blinds. Optimize energy usage and personalize your space for comfort and productivity.

Highlights
  • Activity-based room profiles
  • Energy-saving eco modes
  • HVAC control
  • Lighting dimming
  • Blind adjustment
  • Bluetooth connectivity
Read full description

Take control of your space with the Delta Controls O3 App. Connect with your O3 system via Bluetooth and create profiles to take control of HVAC, lighting, blinds and other peripherals. Dim lights for presentations, optimize energy savings with eco modes or create the perfect lighting for productivity. Coupled with your O3 Sensor Hub, your space knows what you need before you have to ask. Your Room. Your Way. Paired with your O3 system, the O3 app provides: * Configurable, activity-based profiles for each room based on what you’re doing * Eco-friendly profiles to ensure that you can save energy without sacrificing comfort * Communication with your O3 system through Bluetooth ensures your preference carry over to each room

About

Shift Calendar

Organize your work schedule with a customizable calendar designed for shift workers. Track absences, monitor work hours with detailed statistics, and generate exportable reports. Features a dark mode for comfortable viewing.

Highlights
  • Customized shift scheduling
  • Complete absence management
  • Advanced reporting
  • Exportable reports
  • Dark mode
Features
Read full description

ShiftPro is designed for shift workers who want to easily organize their day. With an intuitive and customizable calendar, it helps you manage your work and commitments, making scheduling simple and effective. CUSTOMIZED SHIFT SCHEDULING • Create and manage your work shifts in a simple and flexible way, assigning colors, icons, and details like breaks, positions, duration, and multiple shifts. COMPLETE ABSENCE MANAGEMENT • Easily track sick days, work leave, vacation days, and rest days, all in one place, for a clear and comprehensive overview of your absences. ADVANCED REPORTING • Easily monitor your work with detailed statistics on hours worked, overtime, vacation days, sick leave, and work leave. • Generate exportable reports for simpler management and instant sharing. DARK MODE • An attractive and relaxing design to view your shifts even during nighttime. CREATED BY A REAL PERSON ShiftPro is not the product of a faceless large company; it’s made by a real person. Thank you for supporting an app that’s lovingly created and constantly evolving. Every detail, under control. Further Information Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

O34 screens
Shift Calendar4 screens

Verdict

The call

The clearest difference is in-app purchases: O3 at none against Shift Calendar's 8. O3 also leads on rating (5.0 vs 4.7) and iOS requirement (15.2 vs 17.0). Shift Calendar's advantage is update cadence (weekly vs every 12 months). On price, ratings volume, ads 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. Shift Calendar sells 8 in-app purchases, starting at $0.99 per 7 days. O3 asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

O3 holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 2 and 3 respectively.

UpkeepUpdate frequency

O3 ships an update every 12 months, Shift Calendar weekly. The most recent releases landed on November 2, 2026 and November 4, 2026 respectively.

Scorecard5 real differences · 5 level
O3 versus Shift Calendar: the parameters behind the verdict, then further details
ParameterO3Shift Calendar
PriceFreeFree
Rating5.0 (2 ratings) — better4.7 (3 ratings)
Positive reviews—87.8% of reviews
Number of ratings23 — better
Update frequencyEvery 12 monthsWeekly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.2 — better17.0
Further details — not scored
Size7 MB165 MB
Age rating4+4+
DeveloperDelta Intelligent Building Technologies (Canada) Inc.Andrea Agostino Cataldo

Customer experience

O3

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Shift Calendar

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews41 reviews
Positive87.8%
Neutral9.8%
Negative2.4%

Bugs and requests

O3

Not enough reviews yet to summarise bugs or requests.

Shift Calendar

Requested features

2 requests
  • Widget support
  • Larger font size for exports

In-app purchases

None

O3

No in-app purchases

8 purchases

Shift Calendar

Subscriptions8
  • Weekly$0.997 Days
  • Monthly$1.991 Month
  • Weekly$1.997 Days
Show 5 more
  • Monthly$3.991 Month
  • Monthly7 Days trial$3.991 Month
  • Annual$12.991 Year
  • Annual$19.991 Year
  • Annual7 Days trial$19.991 Year

Questions

Is O3 free?
O3 is free to download, with no in-app purchases.
Is Shift Calendar free?
Shift Calendar is free to download, with in-app purchases available.
Which has better reviews, O3 or Shift Calendar?
O3 is rated higher. O3 averages 5.0 out of 5 from 2 ratings, while Shift Calendar averages 4.7 from 3 ratings.
Do O3 or Shift Calendar have ads?
Neither O3 nor Shift Calendar shows ads.
Which is updated more often, O3 or Shift Calendar?
O3 ships an update every 12 months, and Shift Calendar weekly. Most recently, O3 was updated on November 2, 2026 and Shift Calendar on November 4, 2026.

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