Comparison

Mechanical Engineer vs Invoice & Estimate App

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

Head to head
About

Mechanical Engineer

This app provides over 300 essential mechanical engineering formulas across various domains. It allows users to calculate, save, compare, and share results, aiding in project optimization and decision-making. Users can access a limited number of calculations for free, with a subscription unlocking full functionality.

Highlights
  • Over 300 mechanical engineering formulas
  • Covers diverse engineering domains
  • Save and compare formula results
  • Share calculation outcomes
  • Intuitive and practical interface
  • Regular updates based on user input
Features
Read full description

MECHANICAL ENGINEER FORMULATOR – Elevate Your Engineering with Precision For the dynamic Mechanical Engineer and the proactive engineering student, MECHANICAL ENGINEER FORMULATOR stands as the definitive tool that merges practicality with ease of use. Navigate through your engineering challenges confidently with an app crafted for direct, intuitive interaction. Boasting a comprehensive collection of over 300 essential mechanical engineering formulas, MECHANICAL ENGINEER FORMULATOR actively supports a wide array of mechanical engineering domains: • Actuators & Bearings: Execute precision movements and manage loads with authority. • Belts & Boilers: Transmit power efficiently and generate steam reliably. • Brakes & Clutches: Apply stopping power decisively and control torque with finesse. • Elevators & Gears: Operate smoothly and transfer motions effectively. • Fluid Power & Heat Transfer: Control fluids masterfully and manage thermal dynamics skillfully. • Internal Combustion & Kinetic Energy: Generate power robustly and analyze motion with precision. • Metalworking & Plates: Shape materials skillfully and ensure structural integrity. • Plumbs & Power Plants: Direct fluid systems confidently and produce energy proficiently. • Refrigeration & Shafts: Cool systems effectively and rotate components seamlessly. • Springs & Vehicle Drive: Store energy reliably and propel vehicles powerfully. MECHANICAL ENGINEER FORMULATOR empowers you to save and compare formula results, enhancing decision-making for project optimization. Share your formula outcomes effortlessly, enabling seamless collaboration. Given the ever-advancing nature of engineering, we pledge to move forward together with you. If you are looking for a formula not yet featured, or desire an enhancement, just email us. We are committed to listening and incorporating your input into our forthcoming updates. MECHANICAL ENGINEER FORMULATOR is not just an app; it's an essential resource to achieve engineering excellence. MECHANICAL ENGINEER FORMULATOR places the full potential of precision engineering at your fingertips. MECHANICAL ENGINEER FORMULATOR is FREE to DOWNLOAD and view all of the formulas. Users are able to calculate five formulas for FREE. Purchase a subscription to calculate additional formulas. All subscriptions come with a 1-WEEK FREE TRIAL and SUPPORT Family Sharing.

About

Invoice & Estimate App

This app simplifies job cost tracking and professional invoice generation for businesses. It allows for detailed itemization of costs, creation of estimates and payment receipts, and management of payments received and overdue. The app is designed for flexibility across various business types.

Highlights
  • Job cost tracking
  • Professional invoice generation
  • Estimate creation
  • Payment receipt generation
  • Overdue payment tracking
  • Customer and material management
  • Data sync across devices
Features
Read full description

Pro Invoicer is a must-have app for any business. It makes the process of tracking job costs and generating professional invoices incredibly easy. It also generates job estimates and payment receipts, and keeps track of payments received/overdue. In summary it has the following features: - Maintains an itemised list of all costs associated with each job. - This can include materials/parts, labor costs (chargeable by the hour/day etc), and service costs (work charged as a whole, and not by the day/hour). - Fitting/installation costs for materials can be entered. - Clear summary of the job costs. - Has the flexibility to be suitable for any type of business, including sole proprietors. - The option of entering material costs with or without sales tax included. - The option of adding a markup percentage to material costs. - The option of adding sales tax on top of labor/service/fitting costs. - Multiple sales tax rates can be used if required. - Easy to generate estimates, which can be emailed to the customer (or printed) for their approval. - Easy to generate invoices, containing an itemised list of the costs/taxes, payments received, balance due, and payment instructions/notes. - Job items can be grouped into categories for easier tracking, and for clearer listing on estimates/invoices. - The ability to record which materials have been purchased, or not. - Stores details of payments received, and calculates any outstanding payment due. - Generates payment receipts, which can be emailed to the customer, or printed. - Generates a notification if a payment is overdue. - Take/store photos associated with each job. - Maintain a list of customers, job locations, and previously used materials, labor and service items. - No account/login required - all job data is held only on the app. - Search function to search the lists of jobs, customers, materials, etc. - Can list jobs for a selected customer, job status, date range or cost range. - Syncs data between different devices, (eg. iPhone and iPad), which are logged into the same iCloud account. - Comes with a 60 day free trial. Terms of use: https://smcanalysts.wordpress.com/iap-terms-of-use/

Screenshots

Mechanical Engineer4 screens
Invoice & Estimate App4 screens

Verdict

The call

The clearest difference is review sentiment: Invoice & Estimate App at 100% against Mechanical Engineer's 30%. Invoice & Estimate App also leads on rating (5.0 vs 4.4) and in-app purchases (none vs 3). Mechanical Engineer's advantage is price (Free vs $2.99). On ratings volume, update cadence, 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

Mechanical Engineer is free to download; Invoice & Estimate App costs $2.99 up front. Mechanical Engineer sells 3 in-app purchases, starting at $0.99 per month. Invoice & Estimate App asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Invoice & Estimate App holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 8 and 4 respectively. Written reviews point the same way: 30% of Mechanical Engineer's written reviews are positive against 100% of Invoice & Estimate App's.

UpkeepUpdate frequency

Mechanical Engineer ships an update every 2 months, Invoice & Estimate App every 3 months. The most recent releases landed on October 23, 2026 and October 12, 2026 respectively.

Scorecard6 real differences · 4 level
Mechanical Engineer versus Invoice & Estimate App: the parameters behind the verdict, then further details
ParameterMechanical EngineerInvoice & Estimate App
PriceFree — better$2.99
Rating4.4 (8 ratings)5.0 (4 ratings) — better
Positive reviews29.6% of reviews100.0% of reviews — better
Number of ratings8 — better4
Update frequencyEvery 2 months — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.612.2 — better
Further details — not scored
Size5 MB2 MB
Age rating4+4+
DeveloperHistorycentral.comSMC Analysts Ltd

Customer experience

Mechanical Engineer

All ratings8 ratings
Positive75.0%
Neutral25.0%
Negative0.0%
Written reviews27 reviews
Positive29.6%
Neutral18.5%
Negative51.9%

Invoice & Estimate App

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

3 purchases

Mechanical Engineer

Subscriptions3
  • Monthly Subscription7 Days trial$0.991 Month
  • Pro Quarterly$0.993 Months
  • Pro Yearly7 Days trial$2.991 Year
None

Invoice & Estimate App

No in-app purchases

Questions

Is Mechanical Engineer free?
Mechanical Engineer is free to download, with in-app purchases available.
Is Invoice & Estimate App free?
Invoice & Estimate App costs $2.99, with no in-app purchases.
Which has better reviews, Mechanical Engineer or Invoice & Estimate App?
Invoice & Estimate App is rated higher. Mechanical Engineer averages 4.4 out of 5 from 8 ratings, while Invoice & Estimate App averages 5.0 from 4 ratings.
Do Mechanical Engineer or Invoice & Estimate App have ads?
Neither Mechanical Engineer nor Invoice & Estimate App shows ads.
Which is updated more often, Mechanical Engineer or Invoice & Estimate App?
Mechanical Engineer ships an update every 2 months, and Invoice & Estimate App every 3 months. Most recently, Mechanical Engineer was updated on October 23, 2026 and Invoice & Estimate App on October 12, 2026.

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