However, it requires Oracle Client installed. I always have installed Oracle Server for development at local, so this is not an issue to me.
About 3 years ago, I switched to Win 7 64bit and installed Oracle Server 64 bit for development. The SQLTools++ does not work any more with this error:

The application was unable to start correctly (0xc000007b).

Solution

1. Download a 32bit Oracle Instant Client.
   
2. Extract the Oracle Instant Client to a folder. E.g. d:\oracle\instantclient_12_1\.
   
3. Add the folder into system PATH.
   
4. Start SqlTools (or SqlTools++) again. It can be run up successfully.