SafayJoy , a company that provides online taxi booking service in Nepal. The setup is fairly easy. Simply download the app from the app store, sign up and login. After a few minutes of installation and login, the app lets you choose your destination and you can book among the taxis shown in the app.
The ride charges are as per the government mandated rate. You also get to know the estimated fare before booking a taxi. The downside is that you require a constant internet connection for the app to work.