Tree Studio is described as 'product born from TwistedBrush Pro Studio but with a focus on 2D tree creation with a simpler, streamlined interface. Tree Studio has pairs of brushes for each tree type - one for the frame and one for the leaves' and is an app in the Photos & Graphics category. There are more than 25 alternatives to Tree Studio for a variety of platforms, including Windows, Mac, Linux, iPad and Online / Web-based. The best alternative is GIMP, which is both free and Open Source. Other great apps like Tree Studio are Krita (Free, Open Source), Adobe Photoshop (Paid), Paint.NET (Free Personal) and Affinity Photo (Paid).
Krita is a professional Free and open source (FOSS) painting program. It is made by artists that want to see affordable art tools for everyone withith concept art, texture and matte painters, illustrations and comics.
MyPaint is a fast painting program with an emphasis on full-screen use. It lets you focus on the art instead of the program. You work on your canvas with minimum distractions, bringing up the interface only when you need it.
PaintTool SAI is high quality and lightweight painting software, fully digitizer support, amazing anti-aliased paintings, provide easy and stable operation, this software make digital art more enjoyable and comfortable. Details: - Fully digitizer support with pressure.
MediBang Paint is a lightweight software for illustration and making comic books on Windows and Mac OS. Features -You can save multiple pages in one file. -Perspective grids for easily drawing backgrounds or speed lines.