Hi there,
making first steps with retool I am looking for a dashboard app displaying KPI and charts. All I found were dashboards for web. Or I am doing wrong and can I convert als this web App into native Apps?
Thanks for reaching out & welcome to Retool!
We don't currently have a way to convert web apps to native mobile apps. We are tracking requests for this feature, as it sounds like we hope to support this in the future 
We don't have a timeline on when we'd be able to support this, but I'll add your +1
In the meantime, I recommend checking out our quick start tutorial for mobile & then starting your dashboard from a blank mobile app. I definitely recommend reaching out here on the forum as questions come up! It sounds like you'd want to leverage the chart component, which is powered by Plotly.
Our web app product, which currently has more template examples, can be configured for mobile web browsers. All components appear on the desktop layout by default. The mobile layout is enabled when you configure at least one component to show on mobile. Apps automatically switch to the mobile layout when the viewport width is less than 600px wide.