Google voice

You can use google voice (voice.google.com) to make your reminder calls and call back as the callhub dialer cannot be used like a phone to dial an individual specific phone number.

if you need to know more, just google "how do I set up a google voice number"

1. You can have multiple google voice numbers.  You can have multiple gmail addresses and you can have  google voce number for each gmail address. However, each time you set up a google voice number, google asks you for our own mobile number.  If you have used that mobile number to set up a previous google voice number, it may not allow you to set up another google voice number.

2. get other numbers for these other free services like google voice:

Talkatone

Call2Friends

Ievaphone

PopTox

TextNow

(note: I have not tested these websites or services)

If you get a number with a different area code from each service, you will have multiple caller id numbers for outbound calls