I've made this #linux app for typing in Manglish and other Indian languages with predictive transliteration.
It's very easy to install with @FlatpakApps@twitter.com !
It's a frontend for the amazing library http://varnamproject.com made by @firstname.lastname@example.org !
Install - https://subinsb.com/varnam
It might even be installable in Windows with the new @email@example.com Subsysyem for Linux.
Haven't tried it out, but it may work !
More about Varnam : It's fast, offline and free software (both in libre and cost :P) !
ഫെഡറേറ്റഡ് സോഷ്യൽ വെബ്ബിലെ മലയാളിക്കൂട്ടം.