Comparison

Watto vs 21energy

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

Head to head

Watto

Hourly Electricity Prices

Heater Setup and Configuration

Free

🔧 Utilities

No ratingsView app →

About

Watto

Features

Read full description

- Hourly prices for EPEX SPOT AT and DE - Shows you the best times to charge - Calculates the real price based on your fee structure - Alerts you when the price drops below a set limit - See historical data like average price per week and best weekday

About

21energy

Easily set up and configure your Ofen and Ofen Pro heaters. Connect your device via Bluetooth to your local WiFi and manage your mining pool settings with just a few taps.

Highlights

Easy setup and configuration
Bluetooth connectivity
WiFi connection
Mining pool configuration
Ofen and Ofen Pro support

Read full description

The 21energy app is the easiest way to setup and configure your Ofen and Ofen Pro with just a few taps. Connect your heater via Bluetooth to your local WiFi and configure your mining pool.

Screenshots

Watto4 screens

21energy4 screens

Verdict

The call

The clearest difference is in-app purchases: 21energy at none against Watto's 4. 21energy also leads on update cadence (fortnightly vs every 2 months) and iOS requirement (15.0 vs 18.0). On price, 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. Watto sells 4 one-off in-app purchases. 21energy asks for nothing beyond the download.

UpkeepUpdate frequency

Watto ships an update every 2 months, 21energy fortnightly. The most recent releases landed on October 25, 2026 and October 20, 2026 respectively.

Scorecard3 real differences · 5 level

Watto versus 21energy: the parameters behind the verdict, then further details
Parameter	Watto	21energy
Price	Free	Free
Positive reviews	—	16.7% of reviews
Update frequency	Every 2 months	Fortnightly — better
Ads	No	No
In-app purchases	Yes	No — better
Monetization	—	Free
Devices	iPhone	iPhone, iPod — better
Requires iOS	18.0	15.0 — better
Further details — not scored
Size	4 MB	43 MB
Age rating	4+	4+
Developer	Erik Aigner	21energy GmbH

In-app purchases

4 purchases

Watto

One-time4

Small Tip$0.99
Medium Tip$2.99
Large Tip$3.99

Show 1 more

Extra Large Tip$8.99

None

21energy

No in-app purchases

Questions

Is Watto free?

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

Is 21energy free?

21energy is free to download, with no in-app purchases.

Do Watto or 21energy have ads?

Neither Watto nor 21energy shows ads.

Which is updated more often, Watto or 21energy?

Watto ships an update every 2 months, and 21energy fortnightly. Most recently, Watto was updated on October 25, 2026 and 21energy on October 20, 2026.