tonestro, published by fun.music IT GmbH, has 3,299 App Store ad records tracked in the last year, across all 25 EU storefronts. That is more than Yousician (1,181), Chordify (1,098) and flowkey (816) added together, and it puts tonestro among the three heaviest accounts in EU music learning alongside Simply Piano (3,861) and Ultimate Guitar (3,276). Outside the category, almost nobody has heard the name.
It got there on one English sentence. "Learn to play an instrument" runs in all 25 storefronts, Apple marks its first impression as older than the published one year window, and it was still recorded on 25 July 2026. The headline never changes. The line underneath it does, and that line sells flute, saxophone, trombone, trumpet and clarinet while every other big advertiser in the category is bidding on piano and guitar.
Everything below comes from Apple's public Ad Repository, the transparency dataset the EU Digital Services Act requires. It shows every App Store ad an advertiser ran, where, in what language, and for how long. Apple lists the legal entity as fun.music IT GmbH. The data window ends 26 July 2026, and the most recent impressions in it are dated 25 July 2026.
One headline, twenty five storefronts
tonestro has 12 distinct creatives in the window and only 6 headlines behind them, because Apple counts the same copy twice when it runs as an icon ad and as an icon plus asset ad.
The English headline is the account. "Learn to play an instrument" carries 769 records on its own, runs in all 25 storefronts, and Apple dates its start past the one year mark, so it was already live before this data begins. No other advertiser in the category holds a single line across every EU storefront for that long.
Compare the coverage. tonestro buys in 25 storefronts. Yousician buys in 12, flowkey in 11, Chordify in 9. Seven advertisers in the whole category have recorded volume in all 25 markets, and only two of the seven sell lessons. Width came first here, and it came in English.
The test sits in the promotional text
Under that fixed headline, the promotional text follows one template: learn a named instrument with step by step lessons, live feedback, a sheet music library and a tuner. The instrument in the slot changes. Across 576 records in that template, five instruments show up:
- flute, 128 records
- saxophone, 126 records
- trombone, 120 records
- trumpet, 116 records
- clarinet, 86 records
Not one of them is piano or guitar. Every other heavy advertiser in the category leads with those two. Simply Piano runs "Piano Songs & Lessons". flowkey runs "Piano songs and lessons". Chordify runs "Play Guitar, Piano and Ukulele". Yousician runs "Guitar, Bass & Singing Lessons". Two of those apps collide so hard that Simply Piano and flowkey are running word for word identical German copy in Austria and Germany and word for word identical French copy in France.
This is a claim about tonestro's ad copy, not about its product, which covers more instruments than five. What the copy shows is a bidding decision. The band room instruments have their own searches, their own intent, and far fewer people shouting into them.
The structure is worth copying on its own. The headline is the thing you would have to relaunch to change, so tonestro leaves it alone and does its variation in the field below, where five versions can run side by side without touching the line that is already working.
It ran English only until May 2026
For most of the window there is no local language copy at all. The first non-English creative is dated 19 May 2026, and localization arrived in two dated waves nine days apart:
- 19 May 2026: France and Portugal
- 29 May 2026: Germany and Austria, Italy, Portugal again, Spain
Five local headlines came out of it. France gets "Apprends un instrument". Austria and Germany get "Lerne ein Instrument". Italy gets "Impara a suonare". Spain gets "Aprende a tocar". Portugal gets the sixth line, which is the reason for the next section. The app name localizes too, so the store listing next to the ad reads "tonestro - Cours de Musique" in France and "tonestro - Clases de Música" in Spain.
Two waves, nine days apart, one build each. That is a single afternoon of copy work repeated once, not a rolling localization programme.
The Portuguese slot carries a Polish headline
Here is what the public data shows for Portugal.
tonestro's Portuguese creative is tagged pt-PT, runs only in the PT storefront, uses the correctly localized app name "tonestro - Aulas de Música", and carries correct Portuguese promotional text. Its headline is "Naucz się grać", which is Polish for "learn to play". Two creative groups, 15 records, first recorded 19 May 2026, still recorded at the window end of 26 July 2026.
Meanwhile tonestro's Poland storefront has 215 records, and every one of the 50 records Apple returned for Poland is English, under "Learn to play an instrument".
Across the 11,022 records we retrieved for the whole category, pl never appears as a language tag. The only Polish copy anywhere in the dataset is the line running in Portugal.
We can say what the fields say and no more. We cannot tell from the repository whether this is an error, a leftover, or a deliberate test, and the data carries no explanation. It also stayed live for the last two months of the window, which is the part a founder should sit with: nothing in an ad account raises its hand when the wrong language ships. A weekly read of your own live creatives, storefront by storefront, is the only thing that catches it.
Nineteen storefronts get English and nothing else
Even after the May localization, 19 of the 25 storefronts tonestro buys in receive English copy only: Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, Greece, Hungary, Ireland, Latvia, Luxembourg, Netherlands, Poland, Romania, Slovakia, Slovenia and Sweden. Ultimate Guitar serves exactly the same 19 markets in English only.
That is not a tonestro quirk. Only 8 language tags appear in the entire category dataset: en-GB, de-DE, fr-FR, it, es-ES, pt-PT, nl and sv. No Polish, Czech, Greek, Danish, Finnish, Hungarian or Romanian copy from anyone. Poland alone takes 215 tonestro records in English.
What it does not buy
Every tonestro record we retrieved sits in App Store search results. It does not buy the product page placement, which only three advertisers in the category touch, and it does not buy the browse tab, which exactly one advertiser touches.
It also runs no video. Across the category, 166 of 11,022 records carry a video asset, 1.5%, and the only three advertisers running any video are two sheet music scanners and the smallest advertiser on the board. The heaviest accounts in music learning are buying static icon ads against typed search intent, and tonestro is the clearest example of it.
What we cannot see
Apple returns roughly the 50 most recent records per country, so for a heavy advertiser we see the recent slice, not the full history. For tonestro we retrieved 1,088 of the 3,299 records tracked, 33%. Every longevity figure here is therefore a floor. The English headline is at least a year old, not exactly a year, and any span can only turn out longer than what we report, never shorter. Apple prints "over a year ago" instead of a date for anything older than its window, which is Apple's marker, not ours.
Records are repository records, a proxy for recorded activity. They are not euros, installs or reach. Nothing in the dataset says what tonestro spends, what it pays per install, or whether the trombone line converts better than the trumpet one. And the window ends 26 July 2026, so "still running" means still recorded then, not today.
What a founder can take from this
- Hold the headline still and test in the field below it. One line, 25 storefronts, more than a year, while five variants churn underneath. The relaunch cost of a headline change is real, and tonestro pays it once.
- Buy the instrument nobody is bidding on. Four apps are fighting over piano and guitar in the same words, two of them literally identically in German and French. tonestro's copy goes after flute, saxophone, trombone, trumpet and clarinet, where the searches are smaller and lonelier.
- Width in English can come before language. tonestro covered every EU storefront in English for the whole window and localized six markets in two waves in May 2026. The other lessons apps localized more languages into fewer countries and reach less of the EU.
- Read your own live ads the way you would read a competitor's. A Polish headline sat in the Portuguese slot for two months with correct Portuguese everything else around it. That is only visible if somebody looks at the creatives country by country.
You can read tonestro's live EU creatives, or your own rivals', the same way we just did. Pull any advertiser's App Store ads ranked by how long each has run, free, no account, in about a minute, with the language and the countries for each line.
Method note: figures are computed from Apple's public Ad Repository (DSA Article 39), swept across all 25 EU storefronts with zero failed country queries, data window 26 July 2025 to 26 July 2026. A creative is grouped by placement, format, headline and asset count, and its span runs from its earliest to its latest recorded impression across those markets. "Still recorded" means the creative appears at the window end, 26 July 2026, which is not the same as today, because the repository lags. Apple returns roughly the 50 most recent records per country, so 1,088 of the 3,299 records tracked for tonestro were retrieved and analyzed, 33%, and every span reported here is a floor rather than an exact age. Category figures cover 22 advertisers and 11,022 retrieved records. Record counts are a proxy for volume, not spend. Longevity is a proxy for performance, not a measured conversion rate.