Comparison

Opus LF vs EF Qatar

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

Head to head

Opus LF

Personal alarm for lone worker

About

Opus LF

Features

Read full description

Opus LF is a personal alarm in your mobile phone. With Opus LF you can easily alert pre-selected receivers who can watch the emergency situation via real time video streaming and follow your location in order to speed response. The app requires login information for use. If you have forgotten your information, we recommend that you contact the Opus LF responsible person to retrieve your information. Continued use of GPS running in the background can dramatically decrease battery life.

About

EF Qatar

Features

Read full description

EF App is a mobile application for the members of Engineers forum Qatar which is intended for connecting the members. EF App helps the members to share their technical & professional requirements within their community, and utilize the opportunities.

Screenshots

Opus LF4 screens

EF Qatar4 screens

Verdict

The call

The clearest difference is update cadence: EF Qatar at every 5 days against Opus LF's every 3 months. On price, 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

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

Opus LF ships an update every 3 months, EF Qatar every 5 days. The most recent releases landed on September 8, 2026 and March 2, 2026 respectively.

Scorecard1 real difference · 5 level

Opus LF versus EF Qatar: the parameters behind the verdict, then further details
Parameter	Opus LF	EF Qatar
Price	Free	Free
Update frequency	Every 3 months	Every 5 days — better
Ads	No	No
In-app purchases	No	No
Devices	iPhone, iPod	iPhone, iPod
Requires iOS	13.0	12.0 — better
Further details — not scored
Size	82 MB	39 MB
Age rating	4+	4+
Developer	Amigo Systems AB	Anvin Info System

In-app purchases

None

Opus LF

No in-app purchases

None

EF Qatar

No in-app purchases

Questions

Is Opus LF free?

Opus LF is free to download, with no in-app purchases.

Is EF Qatar free?

EF Qatar is free to download, with no in-app purchases.

Do Opus LF or EF Qatar have ads?

Neither Opus LF nor EF Qatar shows ads.

Which is updated more often, Opus LF or EF Qatar?

Opus LF ships an update every 3 months, and EF Qatar every 5 days. Most recently, Opus LF was updated on September 8, 2026 and EF Qatar on March 2, 2026.