Inkpad is described as 'vector illustration app designed from scratch for the iPad. It supports paths, compound paths, text, images, groups, masks, gradient fills, and an unlimited number of layers' and is an app in the Photos & Graphics category. There are more than 25 alternatives to Inkpad for a variety of platforms, including Mac, Windows, Online / Web-based, Linux and iPad. The best alternative is Inkscape, which is both free and Open Source. Other great apps like Inkpad are Affinity Photo (Paid), Adobe Illustrator (Paid), Sketch (Paid) and Vectr (Free).
Design quickly and confidently with Adobe Illustrator software. Sophisticated tools for drawing and typography, along with advanced color controls and creative effects, provide a comprehensive vector graphics environment.
Vectr is a free graphics editor. Vectr is collaborative like Google Docs, and runs both in your web browser and on your desktop as a native app. With an intuitive interface, Vectr is easy to learn and use.
Karbon, component of Calligra Suite , is the scalable vector drawing application in KDE. It allows artists to create complex drawings without losing image quality when zooming in on, or resizing the drawing.
Gravit Designer is a feature-rich vector graphics tool. It is an installable desktop application. It is also a within-browser application for those who prefer this. It has every design feature this writer is aware of within Inkscape, without the recent issues.