Accept the following currencies by adding a "donate" menu option with receiving addresses:
All of these can be accepted easily. There's an android app called "Coinomi" which is free and open source you can use.
Thanks for the idea.
I updated the FAQs for this: https://podcastaddict.uservoice.com/knowledgebase/articles/402793-i-wish-to-donate-how-can-i-support-the-app