The web design market is flooded with a lot of competent tools that help web UI designers crafting the best mobile layouts. A few of them are-
Adobe Experience Design (XD)
Sketch
Origami Studio
Axure RP
Proto.io
OrigamiGraffle, etc.
You can choose any of them as per your product’s requirements and also can search for more tools to get the product designing right. Getting in touch with a reliable mobile app development company would be an added advantage.