Which iOS app should I use to transfer reference images to my canvas with accurate proportions for painting?

Da Vinci Eye is an iOS app designed to assist artists in achieving precise proportions and perspective by using augmented reality to overlay reference images onto physical drawing surfaces. For painters or sketchers who struggle with scaling or aligning complex subjects, this app simplifies the process. Key features include adjustable opacity for the projected image, grid overlays to break down compositions, and the ability to import photos from the device's library. Users can position their iPhone or iPad above their canvas, and the app displays the image in real-time, allowing for accurate tracing or guidance. This is particularly useful for watercolor artists who need a clean outline before applying paint, or for beginners learning to replicate detailed scenes. Reviews indicate that it saves time on preliminary sketches and reduces frustration with perspective errors. However, some users note that optimal performance requires good lighting and a stable setup to avoid calibration issues. The app supports various art mediums, from pencil drawings to acrylics, making it a versatile tool for improving technical skills. While it excels in proportion accuracy, it does not replace fundamental drawing practice but serves as a reliable aid for specific projects.