Windows · AI · Microsoft Store

Rogeha Deutsch C1

German from B2 to C1, practised the way the exams ask for it. An AI writes the exercises for you and checks whether your answer reaches the exercise's goal, so a correct answer in other words still counts.

Version 2.2, for Windows 10 (version 1809) or Windows 11, a download of about 1 MB. Free in the Microsoft Store; the AI needs a key of your own.

Get it from the Microsoft Store

The Rogeha Deutsch C1 window in English. Topic: Mixed (all topics in turn); below it the Road to C1 bar: 0 of 12 topics done, 120 secure exercises to go. The exercise, from Nominal to verbal style, asks to turn a subordinate clause into a noun phrase: 'Weil die Energiepreise stark gestiegen sind, hat das Unternehmen die Produktion vorübergehend gedrosselt.' The answer 'Wegen dem starken Anstieg der Energiepreise …' is graded Acceptable. Below: the corrected sentence, one mistake (wegen dem starken Anstieg → wegen des starken Anstiegs, Case: in written German 'wegen' takes the genitive), a comment, a version phrased at C1 level, and under Meaning 'die Produktion drosseln': weniger herstellen, herunterfahren, to cut back production. The buttons: Check again, Speak, Read aloud, Hint, Show solution, Next; at the top Progress, the DE | EN switch and a menu button. — **An answer graded by its goal.** The nominal phrase is right, so the answer is acceptable; the one slip, the dative after *wegen*, is corrected with the rule behind it, a version phrased at C1 level shows where to go next, and the phrase *die Produktion drosseln* is explained. Rendered by the app itself.

Graded by the goal, not by one answer

Every exercise states what it is practising: put this clause into nominal style, report this statement, make this sentence formal. When you check your answer, the AI judges whether you reached that goal. Different wording that does it still counts, which is how a C1 examiner reads it too.

A clear verdict

Right, acceptable or wrong, shown as a label with an icon. Acceptable means the goal is met with a slip worth fixing.

Minimal corrections

Your own sentence, corrected as little as possible, so you see exactly what changed and nothing more.

The rule behind each mistake

Each mistake with its category (case, word order, register and so on) and a short explanation of the rule.

Phrased at C1 level

After every answer, a more idiomatic version of the sentence: the step from correct German to good German. Idioms, collocations and noun-verb phrases come with their meaning in plainer German and in English.

What it trains

The grammar and style of the C1 exams (Goethe, telc), in twelve topics, each with an example of what its exercises ask for:

Nominal and verbal style (Nominalstil ↔ Verbalstil)Weil die Preise stark gestiegen sind … → Wegen des starken Preisanstiegs …
The passive and its alternatives (Passiversatz)Das Formular muss ausgefüllt werden. → Das Formular ist auszufüllen.
Reported speech (Konjunktiv I)Sie sagt: «Ich habe keine Zeit.» → Sie sagt, sie habe keine Zeit.
Subjunctive II (Konjunktiv II)Hätte ich das gewusst, wäre ich früher gekommen.
Extended participle attributesder Bericht, der gestern veröffentlicht wurde → der gestern veröffentlichte Bericht
Connectors and paired conjunctionsJe früher wir beginnen, desto besser. · nicht nur …, sondern auch …
Noun-verb phrases (Funktionsverbgefüge)entscheiden → eine Entscheidung treffen · berücksichtigen → in Betracht ziehen
Genitive and fixed prepositionstrotz des Regens · angesichts der Lage · sich an etwas gewöhnen
Register: informal to formalDas klappt leider nicht. → Dies ist leider nicht möglich.
Sentence structure and word orderEr hat gestern wegen des Staus den Zug verpasst.
Idioms and collocationsetwas auf die lange Bank schieben (aufschieben) · eine Rolle spielen
Arguing and taking a positionEinerseits …, andererseits … · Ich bin der Auffassung, dass …

Exercises come as gap fills, rewrites, joined sentences, error corrections, register changes and short free answers. Mixed takes all topics in turn, moving on to the one you practised longest ago, and topics you haven't started yet first. The exercises themselves are always in German.

Practice that sticks

Rogeha Deutsch C1 brings exercises back on a Leitner schedule. A wrong answer comes back after three other answers; a right one moves up a level and returns after 1, 3, 7, 16 and then 35 days, until it is mastered. Reviews and new exercises take turns, so a session is never only revision, and only your first try counts: a right answer after Show solution doesn't move an exercise up.

The road to C1

The goal is concrete. A topic is done when ten of its exercises are secure: at level 3 or higher, so right the first time and right again on a review days later. Twelve topics make 120 secure exercises. The main window shows how many topics are done and how many exercises are still to go, and the progress page opens with the same, topic by topic.

The top of the Progress page: today 8 exercises, a streak of 3 days, 100 % passed in the last 7 days (up 5 points on the week before), 45 reviews due, 0 of 108 exercises mastered. Below, Road to C1: 0 of 12 topics done, 8 of 120 secure exercises, 6 %, and a table of the twelve topics with their status (in progress or not started), a bar of secure and practised exercises against the goal of 10, and how many are still to go. — **The progress page**, here for a simulated month of practice, opening with the road to C1. Further down: exercises per day, the reviews due in the next two weeks, the kinds of mistakes you make most, and your latest mistakes with their explanations.

Speak and listen

Dictate your answers

Speak (F2) turns what you say into text in the answer box, with Azure AI Speech set for Swiss Standard German or, without an Azure key, Windows voice typing. Dictated answers aren't marked down for punctuation, capitals or spelling.

Live dictation

With an Azure key, dictation is live: the microphone streams to Azure while you speak, and your words appear in the answer box as you say them, so a long answer of several sentences stays in view. The newest words may still change until Azure is sure of them. Say Komma or Punkt and the mark appears; the status line counts the time, up to three minutes.

Hear it read aloud

Read aloud (F3) reads the exercise and, after grading, the C1 version or your corrected answer. Azure's natural voices are recommended; the Windows voice works offline as a fallback, but sounds much less natural. The Swiss voices Leni and Jan are the default; hear them:

Leni

Jan

«Formen Sie den Nebensatz in eine Nominalphrase um. Infolge des drastischen Anstiegs der Energiepreise hat das Unternehmen seine Produktion vorübergehend gedrosselt.»

Within the free tier

Azure's free tier gives 500,000 characters of read-aloud a month: about 11 hours of speech, or some 2,000 exercises read out with their C1 versions, around 60 a day. Dictation gets 5 hours a month.

Settings shows this month's dictation minutes and read-aloud characters against that allowance, and says so plainly when it has run out.

Dictation tips

Say the punctuation. Pauses never become commas or full stops, so you can stop to think. Say Komma, Punkt, Fragezeichen, Ausrufezeichen, Doppelpunkt or Semikolon (also Strichpunkt) where the mark goes; the word after a full stop, question or exclamation mark starts with a capital.
Punkt can still be a word. After an article or an adjective it stays a noun: ein wichtiger Punkt, zum Punkt kommen.
Sentences are finished for you. A sentence answer gets a capital at the start and a full stop at the end if you didn't say one. Carry on dictating and that full stop goes again. Words for a gap stay exactly as spoken.
Watch it as you speak. Speak or F2 starts and stops listening, for up to three minutes at a time. With Azure the words appear in the answer box as you say them, and the status line shows the time used. Each dictation is added to what is already there, where you can also correct it by typing. If the live connection drops, the whole recording is transcribed once you stop.
Spelling isn't held against you. A dictated answer is graded on its German, not on punctuation, capitals or spelling the recognition got wrong.
If nothing arrives, speak a little closer to the microphone, and check that Windows lets desktop apps use it (Settings → Privacy & security → Microphone).
Without an Azure key, Windows voice typing does the listening. It needs the Windows language German (Germany) with speech recognition; the app switches the keyboard to it while you dictate and back when you check. If its microphone is off, click it.

Your AI, your key

You choose the AI that writes and grades the exercises: Anthropic (Claude), OpenAI, Google (Gemini), or any server with an OpenAI-compatible interface, including a model running on your own PC. You use your own key, stored encrypted for your Windows account, and the app lists the models that key can use. There is no account with Rogeha Studio and nothing to subscribe to.

What it costs you

Settings estimates this month's AI cost per provider from its list prices, against a monthly budget you set, with a link to the provider's own usage page.

Which key is in use

Settings shows the key each provider uses by its last four characters, and whether it is saved, comes from an environment variable or is missing, so you always know whose account is paying.

Patient with busy servers

When a provider is overloaded, the app tries again after 3 and then 8 seconds before telling you, instead of reporting a lost connection. If your account has run out of credit, it says so and links to the provider's billing page.

In German or English

A DE | EN switch at the top right changes every text in the window and on the progress page. The AI writes its explanations, goals and hints in both languages at once, so switching is instant and costs nothing. German text uses Swiss spelling, with ss for ß.

Private by design

Your exercises, answers and progress stay on your PC. Only what a feature needs goes out, straight from your PC to the AI provider and, if you set it up, Azure AI Speech, under your own keys. Rogeha Studio receives none of it. From version 2.2, the feature overview loads this page from rogehastudio.com when you open it, as a browser would, and sends nothing of yours with it.

Backed up every day. Once a day the app saves your exercises, answers and settings as a zip in your Documents folder, under Rogeha Deutsch C1\Backups, keeping the last 14 days; if OneDrive syncs your Documents folder, the backups go there too. Settings can export and import them, and after a reinstall the app takes over the newest backup by itself.

Read the app's privacy policy →

Under the hood

Version 2.0 is the same app rebuilt as a native Windows program in Rust: one program of about 1.9 MB in a 955 KB package, where the first version, built on .NET, needed 59 MB. The texts, the prompts, the review schedule, the look and your data stay exactly as they were.

App: Rust and plain Win32 windows, laid out for each monitor's scaling, in the Rogeha Studio design system's colours, light and dark following Windows even while the app runs. Only one copy runs: starting it again brings the open window to the front.
Responsive: Everything slow (an AI request, speech, the microphone) runs on a worker thread, so the window never freezes; the next batch of exercises is fetched in the background before you run out.
AI: Plain HTTPS to every provider, answering in structured JSON: a strict schema where the provider supports one, the schema in the prompt where it doesn't. An answer either fits the schema or fails with a clear reason.
Voice: Azure AI Speech for the neural voices and for dictation, which streams the microphone in 100 ms pieces over a WebSocket: the first words show after about a second, then update several times a second; the Windows voice and Windows voice typing as fallbacks.
Progress: A page drawn from your own data and shown in WebView2, with charts on the studio's depth ramp; it opens in under a second.
Overview: From version 2.2, Feature overview in the ☰ menu shows this page in a window of the app, in the same WebView2; links to rogehastudio.com stay there, anything else opens in its usual app.
Tested: 74 automated tests for the review schedule, both languages, the AI's answers and errors, speech, live dictation and backups, test modes that render every window off-screen in both themes and languages, and live checks with Claude, OpenAI, Gemini and Azure.
Data: Plain JSON files in the app's own folder, encrypted keys, and a daily zip backup in Documents.
Package: A 964 KB MSIX for the Microsoft Store, with nothing to install beside it.

Where it stands

Rogeha Deutsch C1 is in the Microsoft Store, free, since October 2026. It runs on Windows 10 (version 1809) and Windows 11, and updates arrive through the Store. It needs a key from one of the AI providers to write exercises; Azure speech is optional.

The current version is 2.2, published on 18 October 2026. Feature overview, new in the ☰ menu, shows what the app can do on this page, right in the app, without opening a browser.

Version 2.1, the first update, brought live dictation, so your words appear while you speak, for answers of up to three minutes; Settings recommends the natural Azure voices over the Windows voice; and starting the app a second time brings the open window to the front instead of opening another copy.

Questions or feedback? Write to support@rogehastudio.com.

All projects →