No signup required. The button is in the header on every page, or go straight to /app. You'll land on a single empty panel with one device frame in it.
Three ways to get a screenshot into the editor:
Click the "Text" button in the left-hand Add-buttons panel. A new text layer drops onto the canvas — drag it where you want, edit it from the properties panel on the right.
For App Store carousels, captions read best in the top quarter of the panel. We dropped the typical safe-area guidance in the aspect ratios guide.
Click the "+" button between panels or below the carousel to add a new panel. Each panel is its own editable surface, but the background gradient flows across all of them unless you override it per-panel. For "spanning" elements (a wave that crosses all panels, for instance), toggle the "Span over all panels" option on any layer.
Export is the one Pro-gated feature. Click "Export" in the header → pick which sizes you want (6.9" iPhone, iPad 13", etc.) → pick locales if you've enabled multi-language → click "Download ZIP". Pro is €20/mo, cancel anytime. See pricing.