Comparison

發球 Serve vs U

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

Head to head
About

發球 Serve

Features
Read full description

打球不用再到處報名,一鍵預約你的場地。

About

U

Features
Read full description

U-Dive is an Apple Watch companion for freediving and snorkel training. Put on your watch, get in the water — it handles the rest. ◆ On Apple Watch • Automatic submersion & dive detection — recording starts hands-free • Live depth and water temperature (depth display capped at 6 m in this release) • Continuous heart-rate recording during dives — watch your mammalian dive reflex • Surface-interval timer with haptic surfacing alert • Custom depth alerts with haptic feedback • Personal max-depth record notifications • GPS entry/exit coordinates for every dive • Action Button support: start a session, flag a dive, review history • Auto Water Lock — long-press the crown to end & save • Built-in dive simulator to try the full flow on dry land ◆ On iPhone • Dive-spot map with favorites, notes and custom icons • Import Google My Maps layers (KML) • Paste a Google Maps share link to create a spot • Full dive log: depth profile, heart rate, duration and coordinates • Share and export your dives ◆ About Lite This release uses Apple's shallow-depth API: depth display is capped at 6 m, while time, heart rate and GPS keep recording beyond it. A full-depth version is in progress. ◆ Requirements • Depth and auto dive detection require an Apple Watch Ultra (depth gauge) • Other Apple Watch models work in manual mode (HR, GPS, timers, log) • The iPhone app manages spots and logs; the watch app runs independently ◆ Safety This app is not a dive computer and must not be used for dive safety or decompression decisions. Not for scuba diving. Freediving is dangerous — never dive alone, follow one-up-one-down, and get certified training.

Screenshots

發球 Serve4 screens
U3 screens

Verdict

The call

The clearest difference is iOS requirement: 發球 Serve at 17.0 against U's 26.4. On price, update cadence, ads and in-app purchases 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 November 5, 2026 and October 29, 2026 respectively.

Scorecard1 real difference · 5 level
發球 Serve versus U: the parameters behind the verdict, then further details
Parameter發球 ServeU
PriceFreeFree
Update frequencyEvery 2 weeksEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
DevicesiPhoneiPhone, Apple Watch — better
Requires iOS17.0 — better26.4
Further details — not scored
Size37 MB10 MB
Age rating4+4+
Developer發球股份有限公司Yao YungTai

In-app purchases

None

發球 Serve

No in-app purchases

None

U

No in-app purchases

Questions

Is 發球 Serve free?
發球 Serve is free to download, with no in-app purchases.
Is U free?
U is free to download, with no in-app purchases.
Do 發球 Serve or U have ads?
Neither 發球 Serve nor U shows ads.
Which is updated more often, 發球 Serve or U?
發球 Serve ships an update every 2 weeks, and U every 2 weeks. Most recently, 發球 Serve was updated on November 5, 2026 and U on October 29, 2026.

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