Joseph Sinfield

Known for

Harp Guru

1app

Top rival

Avi Bortnick

Other rivals

Portfolio

Publisher DNA

AI intelligence is not yet available for Joseph Sinfield. The portfolio data below is up to date.

Top niches they play in

Music Learning Guides1 app

Explore the Music Learning Guides niche

See every app competing in Joseph Sinfield's strongest niche.

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Portfolio

Apps

1 app analysed

Sort by

Harp Guru

3.8(6)

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Chromatic tuning support [Platform: iOS/Android]

Interactive visual mapping [Platform: iOS/Android]
Paid-only entry barrier [Pricing: $4.99]

User sentiment

User-sentiment analysis coming soon.

Rivals

The rivals identified

Same space(4)

Avi Bortnick

known forLyriCue: Memorize Lyrics

1 app

So what?

Strategic outlook coming soon.

Frequently asked questions

How many apps does Joseph Sinfield publish?

Joseph Sinfield has 1 app tracked by Marlvel, primarily in the Education category.

What kind of apps does Joseph Sinfield make?

Joseph Sinfield's portfolio is concentrated in Education, with an average rating of 3.8/5 across rated apps.

Last updated

Harp Guru

v12.1.0

4.6y ago

Single-market publisher — every app ships only to United States.

Based on 1 of 1 app with localized market data · last scanned May 2026.

Americas (1)

United States1 / 1

Core markets (1/1 apps)

United States

Both apps target the niche of amateur musicians seeking to master specific technical performance skills through structured, interactive practice.

Riafy Technologies

known forUkulele Lessons - Learn Chords

1 appEducation

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This app competes for the same beginner-musician demographic by providing instrument-specific guidance and structured learning paths.

The Associated Board of the Royal Schools of Music (Publishing)

known forABRSM Music Theory Trainer

1 appEducation

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This app competes for the same educational music market by offering a structured curriculum that demands high user engagement and technical proficiency.

Xilva

known forPerfect Pitch Practice Pro

1 app1.5Education

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Both apps serve the music education category by providing specialized tools for ear training and instrument-specific technical development.

New entrants(2)

Arctic Surf Designs

known forVolcanoMap

1 app0.0Education

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While in a different niche, it competes for the same 'Education' category attention and demonstrates a modern, data-driven approach to interactive learning.

Goran Ugresic

known forFotoPlant Plant Identification

1 app0.0Education

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What is Joseph Sinfield's top app?

Based on user sentiment and following across the portfolio, Harp Guru stands out as Joseph Sinfield's flagship app tracked by Marlvel.

In how many countries are Joseph Sinfield's apps available?

Marlvel has tracked Joseph Sinfield's apps across 1 country.

This newcomer competes for the user's time within the Education category by offering a utility-focused tool for hobbyist skill development.

Snapshot

Publisher DNA

Top niches they play in

Portfolio

Apps

User sentiment

Rivals

The rivals identified

Same space(4)

So what?

Frequently asked questions

Americas (1)

Core markets (1/1 apps)

New entrants(2)