• Multi Color Space Analysis
  It analyzes the input image in several color spaces to identify the most important aspects that need to be preserved as good as possible. Based on the analysis the tool adjusts the conversion process. By default only the Luv color space is used, it will give pretty good results in most cases. If the conversion is not as good as you hoped it would be you can try to enable other color channels, HSL for example can be quite useful at times. Keep in mind that more enabled color channels will result in a longer conversion process.
  
• Alpha Filter
  You can select a color to treat as transparent in the conversion process. The slider determines how close to the selected color a pixel must be to be detected as transparent. This is useful to remove fuzzy edges with semi-transparent pixels, such as those created by anti-aliasing. However, it is recommended to not use alpha information in the source images, but instead work with transparency colors. This is because a fully transparent pixel will always be read as black (i.e. it loses all color information) and will therefore make black the color to treat as transparent. For my test cases I mostly worked with plain old ugly 0xFF00FF for alpha and 0x0000FF for shadows.
  
• Shadow Filter
  You can select a color to treat as shadow color, i.e. it will get the fitting palette index which is JA2 is rendered as 50% transparent shadow. The filtering works like the alpha filter.
  
• 9 Dither Algorithms
  You can chose between 9 dither algorithms, each with its unique strengths and weaknesses. Default is Sierra Lite.
  
• Color Temperature (30+ Settings)
  You can also set a the color temperature, which can be useful to tone images in the conversion process. By default D65 (6504 K) is used.
  
• Single And Multi Page STIs And Sprite Sheet
  When you drop multiple files on the app, it will generate a sprite sheet with all of the images and build a palette for the sprite sheet. This sprite sheet is saved in the sub folder "sprite sheets". In the same folder as the files a multi page STI is saved. You can toggle the behavior to write each sprite to a single page STI instead.

1. Probably not as a stand-alone, but as a module for JA2STI.

2. Nope, but there's another module for JA2STI in the making that will do that.

Nope, JA2STI is different to this. Let me know if you want to join the JA2STI beta test. This is a side project using a bunch of code written for JA2STI.

You have a pm.