Screenshot Connect is the best app to create app screenshots ready for the App Store.
Drag and drop images, rotate and move the device, add text, export and it is done.
For each screenshot the device is rendered in 3D in real time using Apple Metal framework. Therefore you can rotate, move and adjust the lighting as you want, with real depth and light reflections.
The color of the background can be adjusted as well as the attributes (color, font, size, alignment, etc.) of the text.
6.5 inch iPhone, 5.5 inch iPhone, 3rd gen iPad Pro, 2nd gen iPad Pro and Mac are supported, landscape and portrait.
Screenshots are grouped by template so you preview how the screenshots will look like in the App Store while conceiving them.