In general what're the coolest things Indians have done with Bitcoin tech so far?
I might be off topic here, but I believe exchanges are coolest thing possible at this stage

One I know is blockonoimcs
https://www.blockonomics.co/Regards
Actually a lot of other things would be cool too . Exchanges are plenty , and for within India only 2-3 will do . I am also interested in starting up or working in a start up specially bitcoin related in the future. I really think something along the lines of startups in Philipines would probably get a lot of interest here in India.