I built https://www.indoclinic.com, an online doctor consultation service. The idea is pretty similar to Healthtap/Practo.

We managed to sign up some doctors and got a few users to consult via the platform but ended up closing down the project eventually, mostly due to lack of traction and avenues for differentiation.

Lessons learned: - Do proper user research before starting to code - 'Better customer service' is not really an advantage unless you know how to spread the word and/or are willing to spend years on your product