Recently discovered a great tool

If you’ve finished a mobile app and want to create App Store and Google Play promotional graphics, many options on the market are paid SaaS tools. Since you probably won’t use such a tool very often, subscribing to a monthly SaaS plan feels like a waste.

I recommend a free tool: https://openscrgen.app

It supports screen designs for iPhone, iWatch, Mac, and Google Play. The asset library is huge and the designs look polished.

It goes head-to-head with paid products like theapplaunchpad, previewed, and appscreens.

Open Screenshot Generator | Design & Translate App Store Screenshots

Source: https://openscrgen.app/ Free. Source on GitHub. Runs in your browser

Make your appimpossible toscroll past

Open Screenshot Generator is a design studio for App Store and Play Store graphics. Pick a template, drop in your screenshots, and export every size both stores ask for. Your work stays on your machine unless you invite the AI agent to help

Free forever. No account. No watermark

How it works

Three steps, and that is the whole process

1. Pick a template Open the gallery and choose a starting point. There are designs for fitness, finance, podcasts, games, chat and plenty more, each one already sized for the stores

2. Drop in your screenshots Upload screens straight from your phone or emulator. They snap into the device frames and stay clipped to the glass, even when you tilt the phone in 3D

3. Export for both stores One click renders every artboard at the exact pixel sizes Google Play and the App Store expect. No resizing in another tool and no rejections over pixels

Templates

Start ahead of theblank page

Every set below was designed and exported inside the app. Streaming, meditation, crypto, podcasts, beauty, games. Pick one and make it yours

A dark streaming app screenshot set with gold headlinesA deep green screenshot set for a breathing and mindfulness appA soft pink screenshot set for a beauty subscription appA screenshot set for a crypto portfolio appA colorful screenshot set for a gaming app

What you get

A real design tool, not a screenshot stamper

• Every device that matters iPhone, Android, tablets, Macs and Apple Watch. Rotate them, scale them, or tilt them into 3D poses. Screenshots stay clipped to the glass whatever you do to the frame

• Design tools that respect you Text, shapes, arrows, blobs, speech bubbles and images, all freely placed on artboards with layers and undo across the whole project. A curated set of Google Fonts includes Arabic and Urdu families

• App preview videos too Drop a screen recording into a phone frame, dress it with headlines and tap hints, and export an MP4. A second mode conforms your raw capture to exactly what App Store Connect accepts, so uploads stop bouncing. Video export needs a browser with WebCodecs, like Chrome or Edge, and the desktop app always has it

• An AI agent that does the layout Hand it your screenshots and one sentence about what you want. It picks a template, places every screen in the right frame, and rewrites the copy for your app

• Private by architecture There is no backend. Projects live in your browser storage, exports render on your own machine, and your screenshots never travel unless you hand them to the AI provider you choose. Privacy here is not a policy, it is a missing server

• Automatic Text Translation Localize your graphics for global markets instantly. With a single click, translate all your text elements into over 50 different languages without leaving the editor

• Source in the open, browser and desktop The full source code is public on GitHub. Use it in any modern browser, or grab the desktop app for Windows, macOS and Linux

The AI agent

Upload screenshots. Say what you want.Done

The agent takes your screens plus a sentence like put these in a clean dark template, then chooses the template, fills every frame, and rewrites the headlines for your app. It never draws freehand, so a weak plan gives you an odd design rather than a broken one

• Use my API keyCalls go straight from your browser to Anthropic, OpenAI or Google. Your key stays on your machine
• Free, use my accountWorks with the Claude, ChatGPT or Gemini session you already have open. Fully automatic in the desktop app. In the browser it works through a small companion extension, with a manual copy and paste fallback
• Free, built inThe desktop app ships keyless providers, including local Ollama and LM Studio

The AI agent dialog, asking for screenshots and a sentence about what to build

Nothing leavesyour machine

No account. No analytics. No upload. The editor is a static page, your projects live in your own browser storage, and the exports are rendered locally. You could cut your internet after it loads and keep working on the project you have open. The optional AI agent is the one exception, and it only talks to the provider you pick

Your store page could look bettertonight

Open the editor, pick a template, and export something you are proud to ship

Questions

Fair questions, straight answers

Is Open Screenshot Generator really free?Yes. The editor is free. There is no account, no watermark, and no paid tier. The full source code is public on GitHub

Where do my screenshots go when I upload them?Nowhere. The whole editor runs client side in your browser. Projects and uploads are stored in your browser storage on your own machine, and there is no backend to send them to. That storage is a working copy. Clearing your browser site data deletes it, so treat exported PNGs and MP4s as the real output

Which sizes can it export?The export flow asks which store and which device classes you are targeting, then renders each artboard to PNG at the required dimensions for Google Play and the App Store, including iPhone and iPad sizes

Can it make App Store preview videos?Yes. Drop a screen recording into a phone frame, add your headline and tap hints, and export an MP4. A separate mode conforms your raw capture to exactly what App Store Connect accepts, which is 886 by 1920 at 30 fps in H.264. Encoding happens in your browser and nothing is uploaded. Video export uses WebCodecs, which Chrome, Edge and the desktop app support. On other browsers the export stops with a clear message, and PNG export works everywhere

Does the AI agent need an API key?Not necessarily. You can bring your own key for Anthropic, OpenAI or Google, or use the accounts you are already signed into, like Claude, ChatGPT or Gemini. The desktop app drives the signed in mode automatically. In the browser it works through a small companion extension, with a manual copy and paste fallback. The desktop app also ships keyless providers

Do I need design skills?No. Templates carry the design decisions for you. Pick one, swap in your screenshots, adjust the words, and export. If you enjoy designing, the full editor with text, shapes, fonts and 3D device poses is there too