Comparison

UDAN EMS vs Ruler Studio

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

Head to head

Ruler, Grid & Ring Sizer

Free

🔧 Utilities

No ratingsView app →

About

UDAN EMS

Features

Read full description

The EMS App supports the access and unified control of energy storage, photovoltaic and charging equipment. Support different operators' access, and completely isolate the data of each operator. Flexible generation of daily, monthly, and annual operating data reports and revenue data. For end users of energy storage, it provides power generation and power consumption data viewing, optimizes energy supply, and monitors energy equipment anytime and anywhere through instant reminders and remote access functions.

About

Ruler Studio

Features

Read full description

Precise measuring tools Ruler, grid, calibration, and ring sizing in one clean workspace. Ruler & Grid Studio High-precision multi-unit rulers with a built-in grid for everyday measurements. Smart Ring Sizer Align a real ring with the guide to estimate diameter, circumference, and size. Card Calibration Use a standard card edge to improve real-world measurement accuracy. Free Measuring Toolkit Full-screen grids, scale presets, and measurement overlays are included for everyone. Precise ruler, grid, calibration, and ring sizing tools.

Screenshots

UDAN EMS4 screens

Ruler Studio4 screens

Verdict

The call

The clearest difference is in-app purchases: UDAN EMS at none against Ruler Studio's 1. Ruler Studio's advantage is iOS requirement (13.0 vs 15.0). On price, update cadence, 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. Ruler Studio sells 1 one-off in-app purchase. UDAN EMS asks for nothing beyond the download.

UpkeepUpdate frequency

UDAN EMS ships an update every 5 weeks, Ruler Studio every 6 weeks. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

Scorecard2 real differences · 4 level

UDAN EMS versus Ruler Studio: the parameters behind the verdict, then further details
Parameter	UDAN EMS	Ruler Studio
Price	Free	Free
Update frequency	Every 5 weeks — better	Every 6 weeks
Ads	No	No
In-app purchases	No — better	Yes
Devices	iPhone, iPod	iPhone, iPad, iPod — better
Requires iOS	15.0	13.0 — better
Further details — not scored
Size	34 MB	19 MB
Age rating	4+	4+
Developer	Anhui Udan Technology Co., Ltd.	Spyridon Bousios

In-app purchases

None

UDAN EMS

No in-app purchases

1 purchases

Ruler Studio

One-time1

Ruler Pro Lifetime$2.99

Questions

Is UDAN EMS free?

UDAN EMS is free to download, with no in-app purchases.

Is Ruler Studio free?

Ruler Studio is free to download, with in-app purchases available.

Do UDAN EMS or Ruler Studio have ads?

Neither UDAN EMS nor Ruler Studio shows ads.

Which is updated more often, UDAN EMS or Ruler Studio?

UDAN EMS ships an update every 5 weeks, and Ruler Studio every 6 weeks. Most recently, UDAN EMS was updated on November 3, 2026 and Ruler Studio on October 31, 2026.