Smart phone app question?

I currently have an antique flip phone. I'm considering getting a smart phone soon.

I would like to have an app that allows the phone to ring only when certain people call. Now, I turn off my phones before I go to bed, but for my job, I have to be on call roughly 1 week out of 8. Although I rarely get called, I need to keep the phone on overnight when I'm on call. I want to make sure I don't get unwanted calls from others while I'm sleeping and have to keep the phone on. Also, I want to be able to allow the phone to ring anytime for certain close family members in case there is an emergency.

Is there an app that would do this? If so, do I need a certain type of smart phone or a certain service provider? I intend to go on one of those lower cost plans, no more than $40-$45/month, where I can save money by using a cheaper model instead of getting the latest device with all sorts of fancy features.

2014-09-14T21:35:34Z

Not sure if Insane's answer helps. The way he explains it might not work. This is what I need:
1. During the day while I'm awake, anyone can call me.
2. When I go to bed, no one can trigger a ringtone except for certain selected numbers.
3. Selected numbers of family members can call anytime, all the time.
4. Selected numbers for work/on-call can call anytime, but only during the weeks I'm on call (sometimes they call by mistake so I can't give them permanent access).

2014-09-14T21:43:03Z

5. When I go to bed and wake up, I should be able to turn the ringer off and on in one step, and not have to set ringtones for individual people.
6. The only time I should have to change ringtone settings for individual people is when I go on and off call, then I'll change the settings for the appropriate work/on-call numbers.

Basically, I want a general setting where the ringer can be turned either on or off, and then I want the option to override that setting for some individual numbers.

Anonymous2017-01-21T18:54:40Z

1

Insane_mad_maniak2014-09-14T19:47:57Z

just put on a silent ring tone, then you can customise (with most phones) each person/number in your contacts/phone book, assign a custom ringtone to each person.

this way, when it rings and it's not someone in your contacts/phonebook it will ring with a silent ringtone, people in your contacts/phonebook will ring with the ringtone you assigned.

smartphones do have a poor battery life compared to a none smart phone, you'll have to charge it once a day, so it might be an issue. a second battery or a battery case might be a solution.

Peggy2014-09-14T23:20:47Z

If I were you, I would get a google number/ Skype or Rebtel for work. Just sign out when you don't want to hear from co-workers