PrerAp vs Concrete & Stair Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
PrerAp
This app allows voters to securely store their biographical information and generate QR codes. These codes can then be scanned during enrollment to quickly retrieve data, significantly reducing wait times at registration centers.
- Biographical data storage
- QR code generation
- Reduced registration time
- Data retrieval via scanning
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L'application permet à un électeur d'enregistrer toutes ses données biographiques et de génerer 3 QR Code. Ces 3 QR Code seront scannés par le logiciel d'enrôlement pour recuperer ces données biographiques et ainsi eviter la saisie. Cette application permet de reduire le temps passé dans le centre d'inscription par un réquerant.
Concrete & Stair Calculator
This app provides over 70 construction trade calculations, displaying results in 3D with dimensions. It adapts to local units and rules, offering an AI assistant for job site questions. Organize calculations by project for easy access.
- 70+ trade calculations
- 3D result visualizations
- AI job site assistant (Pro)
- Offline calculations
- Project organization
- Unit and rule adaptation
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Blok is the calculation tool for the modern job site: over 70 trade calculations in your pocket, results drawn in 3D, and Barto, the beaver assistant who answers your job site questions. Built for masons, concrete finishers, roofers, tile setters, drywallers, electricians, plumbers, painters and serious DIYers. THE RIGHT NUMBER, FIRST TIME Pick a trade, enter your measurements: concrete, cement bags, blocks, tile, paint, roof pitch, wire size… The result appears in seconds, with the quantities to order and the points to watch. THE RESULT IN 3D Slab, wall, stairs, roof: what you calculate is drawn in 3D, dimensions included, so you can check everything at a glance before you order. FEET OR METERS, YOUR LOCAL RULES Work in feet and pounds or in meters and kilos. Bag sizes, voltage, installation rules: Blok adapts to the country you choose. BARTO, YOUR JOB SITE ASSISTANT (BLOK PRO) A question about a mix, a slope or a wire size? Barto answers and opens the right calculation, already filled in. He needs an internet connection and can make mistakes: always double-check. YOUR JOBS, ORGANIZED BY PROJECT Keep every calculation for a job in one place and find any number in two taps. THE 10 MODULES MASONRY: concrete volume (slab, round column, stairs, wall, footing), concrete and mortar mix, cement bags, blocks per area, full slab, screed. DRYWALL: panels, screws, tape and mud, studs and tracks, R-value, U-factor. TILING: tile per area, waste, thinset, grout, baseboards, floating floor, vinyl flooring, diagonal layout. PAINTING: wall and ceiling area, paint quantity, primer, wood finish. ROOFING: pitch, rafter length, gable or hip roof area, tiles and slate, battens, lumber sizes, gutters and downspouts, underlayment. ELECTRICAL: Ohm's law, power, wire size, voltage drop, circuit check. PLUMBING: water heater, pipe size, drain slope, radiator and boiler output, head loss. EARTHWORK: excavation, swell factor, tonnage, truckloads, drain slope. GEOMETRY: areas, volumes, Pythagorean theorem and 3-4-5 squaring, trigonometry, proportions. CONVERSIONS: length, area, volume, weight, temperature, pressure, power, feet and inches, AWG… NO SIGNAL NEEDED, NO ADS Calculations work offline, in a basement or out in the middle of nowhere. No account to create. No ads. FREE OR PRO The free version gives you 10 credits to start, then 3 more every Monday, up to 10 (one calculation = one credit). Blok Pro unlocks unlimited calculations, Barto, unlimited projects and favorites, and your calculation history. Monthly or yearly subscription: the price is shown before any purchase. DISCLAIMER Blok's results are indicative. They do not replace local building codes or the advice of an engineer. For any work that affects safety, consult a qualified professional. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. Manage or cancel at any time in your Apple Account settings. Terms of Use: https://blok.devolim.fr/en/legal/terms.html Privacy: https://blok.devolim.fr/en/legal/privacy.html Support: contact.blok@devolim.fr Blok is published by DEVOLIM (BAUGEY MATHEO), a French sole proprietor. SIREN 948 000 757, RCS Bordeaux.
Screenshots
Verdict
The clearest difference is review sentiment: Concrete & Stair Calculator at 100% against PrerAp's 0%. Concrete & Stair Calculator also leads on update cadence (every 5 weeks vs every 5 months). PrerAp's advantage is in-app purchases (none vs 3) and iOS requirement (12.0 vs 15.0). 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
Both are free to download. Concrete & Stair Calculator sells 3 in-app purchases, starting at $2.99 per month. PrerAp asks for nothing beyond the download.
PrerAp ships an update every 5 months, Concrete & Stair Calculator every 5 weeks. The most recent releases landed on October 7, 2026 and October 28, 2026 respectively.
| Parameter | PrerAp | Concrete & Stair Calculator |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (2 ratings) — better | — |
| Positive reviews | 0.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 2 — better | — |
| Update frequency | Every 5 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 29 MB | 42 MB |
| Age rating | 4+ | 4+ |
| Developer | Evolve (RDC) | Devolim |
Customer experience
PrerAp
Concrete & Stair Calculator
In-app purchases
PrerAp
No in-app purchases
Concrete & Stair Calculator
- Blok Pro Monthly$2.991 Month
- Blok Pro Yearly$17.991 Year
- Blok Pro Lifetime$29.99
Questions
Is PrerAp free?
Is Concrete & Stair Calculator free?
Do PrerAp or Concrete & Stair Calculator have ads?
Which is updated more often, PrerAp or Concrete & Stair Calculator?
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