Voiceover generator for app demos and launch videos
Indie developers and agencies ship screen recordings with professional voiceover without hiring actors for every release.
Build the Android app, record the walkthrough, generate voiceover, publish the video—credits unify both product surfaces.
Demo video pipeline
Script the happy path (login → core action → result), generate voiceover MP3, align in your editor with captured footage, export for Product Hunt or Play listing.
Localize demos by regenerating voiceover per language while keeping the same screen capture when UI is localized on the web.
Demo script structure: problem, tap, result
A store video is watched by someone deciding whether to install, not someone learning the app. Structure it as: the problem in the user's words (5s), the first tap that fixes it (10s), the visible result (10s), and one line on what happens next (5s). Under 30 seconds is normal; anything longer loses the install decision to the skip.
Describe what is on screen at the moment it is on screen. The narration and the recording should agree frame by frame — "tap Build, and the signed APK appears in your dashboard" while the dashboard is visible. Narration that describes a different screen than the one being watched is the most common reason a demo feels fake.
Studio-free production that still sounds produced
Record the screen first, silently, at 60 fps. Cut it to the story, then generate narration to the cut. Doing it in that order means the script follows the footage instead of the footage being stretched to fit a script, and it removes the usual re-take loop.
Keep the music bed 18-20 dB under the voice and end with two seconds of music only, so the video does not stop dead on the last word. Export the audio at 48 kHz for video; the generated MP3 is already clean, so avoid stacking additional noise reduction, which is what makes narration sound underwater.
Reusing demo audio across the store, the site, and ads
One well-written demo yields three assets: the full cut for the Play Store listing, a 15-second version for the site hero, and a 6-second loop for paid social. Generate the narration as separate beats — problem, tap, result — and the shorter cuts are assemblies of existing audio rather than new generations.
Re-record only what changed between releases. When a screen moves, regenerate the sentence that describes it and re-cut that beat; the rest of the audio, the music bed, and the pacing stay untouched. That is how a small team keeps store videos current instead of shipping last year's UI for three releases.
Frequently asked questions
Can the same credits build my app and voice the demo?
Yes. APKBuild.org uses one unified credit wallet for APK/AAB builds and AI voice generation. Top up once on the pricing page and spend on either.
How much does AI voice generation cost on APKBuild.org?
Pricing is unified: $1 = 100 credits and AI voice generation uses 15 credits per minute—about 6.5 minutes of standard voice per $1. Credits are shared with APK and AAB builds, so one wallet covers Android packaging and AI voice generation.
Can I use the narration in a Google Play store listing video?
Yes, it is your audio. Play accepts a YouTube-hosted video for the listing, so publish the cut on YouTube (unlisted works) and paste the link. Keep the video free of device frames that imply a different platform and make sure every claim in the narration is true of the build being reviewed.
How do I update a demo after a UI change?
Keep the script in beats and the audio files named by beat. Regenerate only the beat that mentions the changed screen, replace that clip on the timeline, and re-export. The rest of the narration stays identical, which keeps the demo consistent across releases.
Do I need a microphone at all?
Not for the demo narration. You need a quiet room only if you are recording a human voice; generated narration needs nothing but the script. If you mix generated narration with your own recorded segments, match loudness and room tone so the switch is not audible.