Comparison

Battery Grapher vs SharpKnife Pro

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

Head to head
About

Battery Grapher

This app tracks your device's battery usage over time and uses your historical data to predict future battery levels. It's designed for low energy consumption and offers customizable notifications to help you manage charging times.

Highlights
  • Historical battery level graphing
  • Smart future battery predictions
  • Low energy consumption design
  • Customizable battery notifications
  • Supports all complications and widget sizes
Features
Read full description

Battery Grapher graphs your historical battery levels and learns your habits to make smart predictions on what your future battery levels will be. Developed specifically with energy consumption in mind, Battery Grapher has almost no impact on battery life. SMART PREDICTIONS Battery Grapher uses historical battery levels to intelligently predict what your battery level will be throughout the rest of the day, allowing you to plan when to next charge your device. The longer you have Battery Grapher installed, the more accurate future battery level predictions will be. LOW ENERGY CONSUMPTION Battery Grapher is made for people who want to extend the battery life, meaning that low energy usage is a priority. The app runs a background task only once an hour, and doesn't require a network connection, which keeps energy consumption extremely low. CUSTOMIZABLE NOTIFICATIONS Battery Grapher allows you to set notifications that fit your needs. You can get the app to notify you when you battery drops below a preset percentage, or if you only have a certain number of hours left before your battery runs out. (currently only available on watchOS) ALL COMPLICATIONS & WIDGET SIZES SUPPORTED Battery Grapher supports all complications & widget sizes. Complications can show hours before needing to charge, or battery %. Both complications and widgets are customizable from within the app.

About

SharpKnife Pro

Features
Read full description

SharpKnife is a utility that lets you define knife sharpening systems, creating a list of parameters that can be set for each sharpening session. You then add knife records, which support pictures of your knife. Once you have at least one knife and one sharpening system, you can begin keep track of when and how you sharpened each knife. This version allows backing up your data to iCloud, plus data export in JSON and CSV as well as an improved UI.

Screenshots

Battery Grapher4 screens
SharpKnife Pro4 screens

Verdict

The call

The clearest difference is update cadence: SharpKnife Pro at daily against Battery Grapher's every 2 months. SharpKnife Pro also leads on price ($0.99 vs $1.99). Battery Grapher's advantage is device support (4 vs 2) and iOS requirement (15.0 vs 17.5). On 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

Battery Grapher costs $1.99 and SharpKnife Pro $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Battery Grapher ships an update every 2 months, SharpKnife Pro daily. The most recent releases landed on October 1, 2026 and September 10, 2026 respectively.

Scorecard4 real differences · 6 level
Battery Grapher versus SharpKnife Pro: the parameters behind the verdict, then further details
ParameterBattery GrapherSharpKnife Pro
Price$1.99$0.99 — better
Rating4.3 (153 ratings) — better—
Positive reviews60.7% of reviews—
Number of ratings153 — better—
Update frequencyEvery 2 monthsDaily — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod, Apple Watch — betteriPhone, iPad
Requires iOS15.0 — better17.5
Further details — not scored
Size5 MB6 MB
Age rating4+4+
DeveloperJoshua BirdANNULET CONSULTING, LLC

Bugs and requests

Battery Grapher

Reported bugs

18 issues
  • Widget not displaying on initial installation
  • Complication shows stale data and doesn't refresh automatically
  • Battery percentage stuck at incorrect values (e.g., 73%, 68%)
  • Accuracy status fluctuates rapidly between good and bad
  • Missing data warnings despite app being in dock
Show 13 more
  • Charge-discharge cycle recognition fails (shows straight lines)
  • App crashes on iPad and certain iOS versions
  • Complication capped at 47-48 hours on Apple Watch Ultra
  • Incorrect battery readings after full charge
  • Notifications arrive delayed or not at all
  • App shows charging when device is not charging
  • Data loss after watch pairing/unpairing
  • Graphs display inverted or incorrect usage patterns
  • 24-hour time format setting non-functional
  • Text cutoff on complication at bottom of watch face
  • Accuracy never improves beyond 'bad' status
  • App requires manual watch face switching to update
  • Predictions wildly inaccurate on newer Apple Watch models

Requested features

18 requests
  • Watch complication for Smart Stack (watchOS 10+)
  • Support for Apple Watch Ultra with correct 36-hour battery display
  • Low power mode detection and separate prediction profiles
  • Force refresh button in app
  • More frequent update intervals (user-configurable)
Show 13 more
  • 24-hour time format option
  • Charging time estimation while device is charging
  • Notifications for full charge completion
  • Battery percentage display in widgets
  • MacBook app version
  • App-specific battery drain identification
  • Historical data view (weekly/monthly)
  • Cross-device battery information (iPhone battery on Watch, etc.)
  • Landscape mode graph expansion
  • Multiple widget size options
  • Portuguese/Brazilian Portuguese localization
  • Manual dark mode toggle for iPhone
  • Watch complication for multiple stacks

SharpKnife Pro

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Battery Grapher

No in-app purchases

None

SharpKnife Pro

No in-app purchases

Questions

Is Battery Grapher free?
Battery Grapher costs $1.99, with no in-app purchases.
Is SharpKnife Pro free?
SharpKnife Pro costs $0.99, with no in-app purchases.
Do Battery Grapher or SharpKnife Pro have ads?
Neither Battery Grapher nor SharpKnife Pro shows ads.
Which is updated more often, Battery Grapher or SharpKnife Pro?
Battery Grapher ships an update every 2 months, and SharpKnife Pro daily. Most recently, Battery Grapher was updated on October 1, 2026 and SharpKnife Pro on September 10, 2026.

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