Random FOSS code sharing offer (email metadata/telegram client hacks)
1) I recently wrote a GUI tool for forging basic email metadata (load existing .eml file, change fields in form, save modified .eml file)
2) I recently forked and outfitted one of the official telegram web clients (https://github.com/Ajaxy/telegram-tt) with a few blunt hacks that allow injection of forged message histories into the interface of the otherwise perfectly normal and functional telegram client
Both projects are a little too weird and mischievous (*) that I would like to openly host them as repositories, but if one or the other happens to tackle a usecase of yours, I'm happy to share the code under a free license, let me know!
(*) for the record, they were benevolently used for staging an interactive theater performance (¬‿¬ )