InstaRabbi vs Sundial Builder
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
InstaRabbi
This app provides quick answers to questions about Torah and Judaism, specifically for Orthodox Jewish observance. Users can submit halachic questions and receive responses from qualified Rabbis, ensuring no question goes unanswered.
- Ask halachic questions
- Get answers from Rabbis
- Orthodox Jewish observance
- Quick responses
- Unanswered questions addressed
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How often have you found yourself in the following situations?... You did not know the correct Bracha to make in a particular situation... You had a question that you didn't feel comfortable asking someone who knows you... You consistently feel guilty "bothering" the Rabbi with your "simple questions" all the time... Too often, many of us will convince ourselves that we think we know the correct thing to do and that we are probably right. InstaRabbi is taking your orthodox Jewish observance to the next level by making sure that you never again have to act as your own Rabbi when you don't know what to do, and that none of the questions that you have related to Judaism go unanswered. InstaRabbi allows Jews from across the world to ask Torah or halachic questions and get them answered quickly according to orthodox Jewish observance. Submit a question on the app and await the quick response from our qualified and dedicated staff of Rabbis who are committed to enhancing halachic observance throughout the world.
Sundial Builder
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HORIZONTAL SUNDIAL Built on a flat horizontal surface. - Hour lines converge toward true south in the northern hemisphere, or true north in the southern hemisphere. - The gnomon is fixed at the "center of the sundial," where the hour lines meet, is tilted relative to the horizontal plane by an angle equal to the absolute value of the local latitude, it must point to the celestial north pole (northern hemisphere) or celestial south pole (southern hemisphere). Required data: - Latitude between 5° and 80° (use negative values for southern hemisphere) - Longitude (used only to calculate correction between solar time and civil time) - Location can be entered manually or retrieved via the device's GPS - Gnomon length: between 10 cm and 30 cm. The final tilted length is calculated by the app - Equation of Time and longitude correction are shown on screen and in the CSV file --- VERTICAL SUNDIAL Built on a vertical wall facing any direction (south, west, east, north, or intermediate). - Hour lines start from the "center of the sundial" and extend downward - The gnomon is fixed at this center point - The gnomon is inclined based on latitude and wall orientation. It equals the latitude only when facing due south or due north - The gnomon must point to the celestial north pole (northern hemisphere) or celestial south pole (southern hemisphere) Required data: - Latitude between 5° and 80° (use negative values for southern hemisphere) - Longitude (used only for time correction) - Location can be entered manually or via GPS - Gnomon length: between 10 cm and 30 cm. The app computes the final inclined length - Wall orientation: - Northern hemisphere: from 270° (east) to 360°≡0° (south) to 90° (west) - Southern hemisphere: from 270° (east) to 180° (north) to 90° (west). --- GENERAL NOTES - The scale factor changes the sundial’s visual size but not the CSV values - Sundials near the edge of a time zone may show up to 30 minutes of difference between solar time and civil time - The app calculates the inclined gnomon length from the center - Alternatively, you can place a perpendicular gnomon from the origin point; in this case, only the tip’s shadow indicates the time - Wall orientation is measured clockwise from south: - 0° = South - 90° = West - 180° = North - 270° = East
Screenshots
Verdict
The clearest difference is price: InstaRabbi at Free against Sundial Builder's $4.99. Sundial Builder's advantage is update cadence (every 2 days vs every 4 weeks). On ads, in-app purchases, device support and iOS requirement 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
InstaRabbi is free to download; Sundial Builder costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
InstaRabbi ships an update every 4 weeks, Sundial Builder every 2 days. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.
| Parameter | InstaRabbi | Sundial Builder |
|---|---|---|
| Price | Free — better | $4.99 |
| Rating | 4.9 (445 ratings) — better | — |
| Positive reviews | 97.2% of reviews | — |
| Number of ratings | 445 — better | — |
| Update frequency | Every 4 weeks | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 52 MB | 13 MB |
| Age rating | 12+ | 4+ |
| Developer | InstaRabbi | Pietro Massimino |
In-app purchases
InstaRabbi
No in-app purchases
Sundial Builder
No in-app purchases









