Comparison

Wasser vs Birthify Calendar

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

Head to head
About

Wasser

Features
Read full description

Wasser-Challenge helps you drink enough every day – on your own or together with friends, family, your club or colleagues. Please note: the app is currently available in German only. HOW IT WORKS • Log every glass with one tap: +100, +250, +500 ml or a custom amount • The progress ring shows how far you are today • A drink reminder at the time you choose • View, edit or delete your entries STAY ON TRACK TOGETHER • Rooms for your team, family, club or office – join with a room code • Shared daily goal, leaderboard, streaks and an overview of recent weeks • Cheer each other on with push notifications • New group challenges every week LEVELS AND ACHIEVEMENTS • Earn XP and level up • Daily challenges with bonus XP • 18 achievements to unlock TEAM CHALLENGE OF THE MONTH Every month, teams of at least 4 people compete. What counts are the days on which you reach your daily goal – not the amount. The best team wins a prize, in November €10 by SEPA bank transfer. Taking part is free and voluntary. Official rules (German, binding): https://water.rk-studios.de/gewinnspiel – Apple is not a sponsor and is not involved in any way. YOUR DATA • No account and no e-mail address needed (an e-mail only if you join the team challenge) • Servers in Germany • Manage consents, export or delete your data – right in the app PREMIUM (OPTIONAL) The free version contains ads. Premium removes ads and adds advanced statistics (6-week trend, goal rate, weekday analysis) and extra challenges. Wasser-Challenge Premium is a monthly auto-renewable subscription. The price is shown in the app before you buy. Payment is charged to your Apple ID. The subscription renews automatically unless cancelled at least 24 hours before the end of the current period, and you can cancel it at any time in your Apple ID settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy policy (German): https://water.rk-studios.de/datenschutz Subscription terms (German): https://water.rk-studios.de/abo-bedingungen Note: the app is not a substitute for medical advice. Don't drink beyond your thirst; if you have a medical condition, check your fluid needs with your doctor. Wasser-Challenge is an app by RK Studios UG (haftungsbeschränkt), Halver, Germany.

About

Birthify Calendar

Features
Read full description

Birthify Calendar hilft dir, Geburtstage organisiert im Blick zu behalten. Speichere Geburtstage mit Notizen und Kategorien, organisiere Kontakte in Gruppen und lass dich rechtzeitig erinnern. Für Glückwünsche kannst du wiederverwendbare Vorlagen mit Variablen nutzen, damit Nachrichten schneller vorbereitet sind und trotzdem persönlich bleiben. Funktionen: - Geburtstage übersichtlich verwalten - Erinnerungen für kommende Geburtstage - Gruppen für Familie, Freunde, Teams oder Gemeinden - Kategorien und Notizen pro Kontakt - Wiederverwendbare Nachrichtenvorlagen - Import und Export deiner Daten - Datenschutz- und Löschfunktionen in der App Birthify Calendar ist für alle gedacht, die wichtige Menschen nicht vergessen und Geburtstagsgrüße entspannter vorbereiten möchten.

Screenshots

Wasser4 screens
Birthify Calendar4 screens

Verdict

The call

The clearest difference is in-app purchases: Birthify Calendar at none against Wasser's 1. Birthify Calendar also leads on ads (none vs shown) and update cadence (fortnightly vs every 7 months). On price, device support and iOS requirement 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. Wasser sells 1 in-app purchase, starting at $3.99 per month. Birthify Calendar asks for nothing beyond the download.

UpkeepUpdate frequency

Wasser ships an update every 7 months, Birthify Calendar fortnightly. The most recent releases landed on November 5, 2026 and October 10, 2026 respectively.

Scorecard3 real differences · 3 level
Wasser versus Birthify Calendar: the parameters behind the verdict, then further details
ParameterWasserBirthify Calendar
PriceFreeFree
Update frequencyEvery 7 monthsFortnightly — better
AdsYesNo — better
In-app purchasesYesNo — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.115.1
Further details — not scored
Size40 MB37 MB
Age rating12+4+
DeveloperRobin KaulfussMarten Messiha

In-app purchases

1 purchases

Wasser

Subscriptions1
  • Premium$3.991 Month
None

Birthify Calendar

No in-app purchases

Questions

Is Wasser free?
Wasser is free to download, with in-app purchases available.
Is Birthify Calendar free?
Birthify Calendar is free to download, with no in-app purchases.
Do Wasser or Birthify Calendar have ads?
Wasser shows ads; Birthify Calendar does not.
Which is updated more often, Wasser or Birthify Calendar?
Wasser ships an update every 7 months, and Birthify Calendar fortnightly. Most recently, Wasser was updated on November 5, 2026 and Birthify Calendar on October 10, 2026.

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