Report updated May 5, 2026
Interp Calculator
For students, engineers, technicians, and maritime professionals who require accurate, offline numerical analysis tools.
Interp Calculator is an established utilities app that is free with in-app purchases. With a 4.4/5 rating from 764.6K reviews, it shows polarized user reception. Users particularly appreciate core calculator functionality provides reliable utility for daily arithmetic and store shopping tasks, though post-update ui changes removed the running total display and quick answer functionality remains a common concern.
What is Interp Calculator?
Interp Calculator is a utility tool for linear and bilinear interpolation, designed for students and technical professionals on iOS and Android.
Users hire this app to perform specialized numerical analysis in offline environments where general-purpose calculators lack the necessary grid-based computation logic.
Current Momentum
v9.1 (886477075) · 1mo ago
Maintenance- Ships frequent UI-focused updates.
- Maintains specialized interpolation niche.
What makes this app unique?
What Does It Look Like?
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What Are The Key Features?
Calculates intermediate values between two known data points for tabular data analysis.
Computes values based on four surrounding points in a two-dimensional grid.
Performs all calculations locally without requiring an internet connection.
How much does it cost?
- iOS version priced at $0.99
- Android version available for free
Monetization is split by platform, with a $0.99 one-time purchase on iOS and a free distribution model on Android.
Who Built It?
Stanislav Soroka
Equipping maritime professionals with specialized offline tools for navigation, engineering, and contract management.
Portfolio
8
Apps
What other apps does Stanislav Soroka make?
Explore the full Stanislav Soroka report
Portfolio breakdown, audience, momentum, and every app published by Stanislav Soroka.
What do users think recently?
High confidence · 50 reviews analyzed · Based on 50 reviews. Signal may be noisy.
What is the recent mood?
Recent user voice shows a mixed sentiment. Users appreciate core calculator functionality provides reliable utility for daily arithmetic and store shopping tasks, but report post-update ui changes removed the running total display and quick answer functionality and visual regressions including oversized ui elements and flashing cursors disrupt the calculation flow.
What Users Love
What Frustrates Users
What Users Want
View the full user-sentiment analysis
Mood gauge, ratings & review-volume history, every praise / complaint / request, and sentiment over time.
What is the competitive landscape for Interp Calculator?
How's The Utilities Market?
How does it evolve in the Utilities market?
The app maintains a 4.35 rating on Android with over 760,000 ratings, but the recent update's UI regressions threaten this established base against high-velocity competitors.
Rank progression
5 active rankings tracked — 30-day window
The rivals identified
Nemeses(1)
This app shares the same utility-focused distribution model and massive scale, serving as the primary benchmark for general-purpose calculation tools.
Differentiators
- Maintains a high-frequency update cadence to ensure compatibility with the latest Android OS versions.
- Leverages a massive, established user base to dominate search visibility within the Utilities category.
- Provides a standardized, no-frills interface that prioritizes speed over complex numerical analysis features.
Head to head
The target app should defend its niche by emphasizing its specialized interpolation capabilities, as it cannot compete with the nemesis on general-purpose utility scale.
Contenders(2)
A long-standing utility app that maintains a massive footprint in the same category.
Differentiators
- Focuses on extreme simplicity and minimal UI overhead to reduce cognitive load for casual users.
- Established brand presence acts as a barrier to entry for new, specialized utility tools.
A high-velocity competitor with significant market penetration and frequent feature updates.
Differentiators
- Aggressive release schedule with nine updates in six months indicates a highly active development pipeline.
- Optimized for tablet-first experiences, capturing a segment of the market that requires larger screen real estate.
Same space(3)
A direct category peer that competes for the same general utility search intent.
Differentiators
- Utilizes a generic utility branding strategy to capture broad, non-specific search traffic.
- Offers a standard feature set that prioritizes broad compatibility over specialized mathematical functions.
Adjacent tool that competes for the same technical user base in the Tools category.
Differentiators
- Includes a broader suite of scientific functions that may overlap with interpolation needs.
- Maintains a high update frequency to keep pace with evolving mobile hardware standards.
Targets the same academic and engineering audience but focuses on graphing rather than interpolation.
Differentiators
- Provides advanced visual graphing capabilities that serve as a natural upgrade path for engineering students.
- Positions itself as a comprehensive academic tool rather than a single-function utility.
New entrants(1)
High-velocity development and recent entry suggest an attempt to capture niche technical users.
Differentiators
- Rapid release cadence suggests a willingness to iterate quickly based on user feedback loops.
- Focuses on modernizing the scientific calculator interface to appeal to younger, design-conscious students.
Compare Interp Calculator against every rival
All rivals in one side-by-side table — identity, store metrics, ratings & sentiment, and strategic intel — plus a head-to-head page for each.
The outtake for Interp Calculator
Strengths to defend, gaps to attack
Core Strengths
- Offline-first architecture functions as a switching-cost barrier for maritime professionals
- Specialized bilinear interpolation serves as a technical differentiator
Critical Frictions
- 0.7★ Android-iOS rating gap on majority Android base
- Removal of running total feature in the latest update
- UI scaling issues on Android
Growth Levers
- Home screen widget integration for faster access
- Financial conversion tool expansion for broader utility
Market Threats
- High-frequency update cadence of Calculator #
- UI regressions causing app deletion
- General-purpose calculators adding interpolation as a standard feature
What are the next best moves?
Restore subtotal display because it is the top-cited complaint → stabilize Android rating
Users report frustration over the removal of the subtotal feature during input
Trade-off: Pause the financial conversion tool sprint — subtotal restoration has higher retention impact.
Audit UI scaling on Android because oversized elements cause screen cutoff → reduce churn
The interface appears too large and gets cut off by screen boundaries
Trade-off: Same-quarter capacity available — no major lever displaced.
A counter-intuitive read
The app's primary risk is not a lack of features, but the maintenance-mode trap where UI regressions in a simple utility app cause higher churn than missing complex functionality.
Feature Gaps vs Competitors
- Financial conversion tools (available in stock calculators but missing here)
- Memory functions M+/MRC (available in Calculator! but missing here)
- Home screen widgets (available in Calculator₊ but missing here)
Key Takeaways
Interp Calculator retains a technical user base through specialized interpolation tools, but the latest update's UI regressions threaten retention, so the PM must prioritize restoring core utility features to stabilize the Android rating.
Where Is It Heading?
Declining
The utility calculator market is consolidating around high-frequency update cadences, leaving Interp Calculator exposed to churn if it continues to prioritize UI changes over core functionality. The recent sentiment decline indicates that professional users prioritize calculation efficiency over visual updates, so the PM must pivot to stability to prevent further erosion of the Android install base.
UI regressions in the latest update (oversized elements, missing subtotal) erode the daily active habit, which compounds the rating drag visible on Android.
Recent updates focused on UI changes rather than feature expansion, leaving the app vulnerable to competitors with higher update cadences.