Comparison

U vs SKI+ v2 Prem

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

Head to head

Secure IM with PQC for Ent.

Free

🌐 Social Networking

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About

U

Features

Read full description

Connect, Create, and Explore with Ucom! Dive into vibrant video calls, and engaging chats, and discover meaningful connections through our innovative features. Join the UCOM community and stay close, no matter the distance!

About

SKI+ v2 Prem

Features

Read full description

SKI+ v2 is an end-to-end instant messaging app that utilizes post-quantum encryption algorithms. The encryption and decryption of messages are performed on the mobile device, and the server side cannot access the encryption/decryption details. The enterprise version supports messaging services and data localization, and provides autonomous account and permission management functions. For more details, please refer to https://www.e2eelab.org If you have any usage questions or suggestions, feel free to send related descriptions or screenshots to: ziv@citi.sinica.edu.tw We will address your inquiries as soon as possible.

Screenshots

U4 screens

SKI+ v2 Prem4 screens

Verdict

The call

The clearest difference is ads: SKI+ v2 Prem at none against U's shown. U's advantage is iOS requirement (12.0 vs 17.6). 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

Both ship on a similar rhythm, roughly every 2 weeks. The most recent releases landed on September 20, 2026 and September 15, 2026 respectively.

Scorecard2 real differences · 4 level

U versus SKI+ v2 Prem: the parameters behind the verdict, then further details
Parameter	U	SKI+ v2 Prem
Price	Free	Free
Update frequency	Every 2 weeks	Every 2 weeks
Ads	Yes	No — better
In-app purchases	No	No
Devices	iPhone, iPod	iPhone, iPad
Requires iOS	12.0 — better	17.6
Further details — not scored
Size	210 MB	248 MB
Age rating	17+	4+
Developer	Reda Kuehn	Academia Sinica Research Center for Information Technology Innovation

In-app purchases

None

U

No in-app purchases

None

SKI+ v2 Prem

No in-app purchases

Questions

Is U free?

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

Is SKI+ v2 Prem free?

SKI+ v2 Prem is free to download, with no in-app purchases.

Do U or SKI+ v2 Prem have ads?

U shows ads; SKI+ v2 Prem does not.

Which is updated more often, U or SKI+ v2 Prem?

U ships an update every 2 weeks, and SKI+ v2 Prem every 2 weeks. Most recently, U was updated on September 20, 2026 and SKI+ v2 Prem on September 15, 2026.