Comparison

RR4 Scheduler vs Referee Yellow card, Whistle

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

Head to head

Referee Yellow card, Whistle

judgment of something

Free

🔧 Utilities

★ 4.752 ratingsView app →

About

RR4 Scheduler

Features

Read full description

Scheduling software for the RR4 Clinic

About

Referee Yellow card, Whistle

This utility app provides a digital referee toolkit for sports and other situations. It features a whistle sound and full-screen display of various colored cards for judgment calls. Designed for simplicity, it's suitable for games, training, or even pranks.

Highlights

Whistle sound functionality
Full-screen yellow, red, orange, and green cards
Simple and easy-to-use interface
Suitable for sports refereeing
Useful for training and games
Can be used for pranks

Features

Read full description

It is a simple referee application that can be used in sports etc. It can sound a whistle, can be used for sports refereeing, training, when you want to call something, pranks, etc. You can put out four kinds of cards of yellow card, red card, orange card, green card in full screen. It may be interesting to use it as a referee in sports games or when playing with friends. It is designed to be easy to use with a simple screen and functions, so please try it.

Screenshots

RR4 Scheduler3 screens

Referee Yellow card, Whistle3 screens

Verdict

The call

The clearest difference is ads: RR4 Scheduler at none against Referee Yellow card, Whistle's shown. RR4 Scheduler also leads on iOS requirement (12.0 vs 15.6). On price, update cadence, 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

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

RR4 Scheduler ships an update every 4 months, Referee Yellow card, Whistle every 2 months. The most recent releases landed on October 27, 2026 and November 3, 2026 respectively.

Scorecard2 real differences · 8 level

RR4 Scheduler versus Referee Yellow card, Whistle: the parameters behind the verdict, then further details
Parameter	RR4 Scheduler	Referee Yellow card, Whistle
Price	Free	Free
Rating	—	4.7 (52 ratings) — better
Positive reviews	—	71.4% of reviews
Number of ratings	—	52 — better
Update frequency	Every 4 months	Every 2 months — better
Ads	No — better	Yes
In-app purchases	No	No
Monetization	—	Ad-supported
Devices	iPhone, iPad, iPod	iPhone, iPad, iPod
Requires iOS	12.0 — better	15.6
Further details — not scored
Size	55 MB	15 MB
Age rating	4+	4+
Developer	Christian Petropolis	Ryouhei Azuma

In-app purchases

None

RR4 Scheduler

No in-app purchases

None

Referee Yellow card, Whistle

No in-app purchases

Questions

Is RR4 Scheduler free?

RR4 Scheduler is free to download, with no in-app purchases.

Is Referee Yellow card, Whistle free?

Referee Yellow card, Whistle is free to download, with no in-app purchases.

Do RR4 Scheduler or Referee Yellow card, Whistle have ads?

Referee Yellow card, Whistle shows ads; RR4 Scheduler does not.

Which is updated more often, RR4 Scheduler or Referee Yellow card, Whistle?

RR4 Scheduler ships an update every 4 months, and Referee Yellow card, Whistle every 2 months. Most recently, RR4 Scheduler was updated on October 27, 2026 and Referee Yellow card, Whistle on November 3, 2026.