Affinity Designer is not available for Android but there are a few alternatives with similar functionality. The best Android alternative is Vector Paint. It's not free, so if you're looking for a free alternative, you could try Inker or Omber. If that doesn't suit you, our users have ranked more than 25 alternatives to Affinity Designer and four of them are available for Android so hopefully you can find a suitable replacement.
Vector Paint is a drawing program, with a simple yet powerful interface, that lets you draw points, lines, curves and shapes. Features * Style text * Layer, grid and align objects * Freely export and import files in standard SVG format.
Omber is a new type of vector design program that lets you use color in new ways in your vector drawings. With Omber's advanced soft shading tools, you can easily make dramatic color blends or subtle color gradients in your art.