Hello everyone,
I've finally got time from work and finished the plugin. 
Special thanks to @Nicholas_Bokulich for suggesting making my own plugin, and @thermokarst for revision.
The plugin is available at my github page (see: https://github.com/kaanb93/q2-krona).
Simply, Krona is a tool to create interactive multi-layered pie charts. Here is an example view of the chart below.
q2-krona is developed to make is easy to generate Krona plots, because the tool needs some rearrangement on FeatureTable[Frequency] to be able to work.
For now, the plugin consists of one visualizer and one pipeline. There might be some additions later on.
PLOT
This visualizer takes FeatureTable[Frequency] as input. But, I strongly suggest to use a collapsed table because this visualizer does NOT use reference taxonomy.
COLLAPSE AND PLOT
This pipeline uses taxa collapse method to use reference taxonomy with FeatureTable[Frequency] taken as input and krona plot visualizer to generate Krona plots. Collapse level and taxonomy delimiter are definable.
Here, I used feature table filtered to 2k minimum frequency and taxonomy from Parkinson's Mouse Tutorial to test the plugin.
Files:
https://docs.qiime2.org/2021.8/data/tutorials/pd-mice/table_2k.qza
https://docs.qiime2.org/2021.8/data/tutorials/pd-mice/taxonomy.qza
qiime krona collapse-and-plot \
--i-table table_2k.qza \
--i-taxonomy taxonomy.qza \
--o-krona-plot krona.qzv
Output:
krona.qzv (401.0 KB)
The visualizer is viewable at QIIME 2 View.
Hope this plugin helps all QIIMErs. I can take suggestions/critiques on this forum or the github page.
Best wishes,
