I have a Cat Eye trip computer on one of my bikes and like it. I would like to have more info about my rides though such as cadence, altitude changes , and mapping.

I understand you can get smart phone apps that will provide this and other input. Problem is I don't have a smart phone and don't want one. I really hate having to pay the monthly premium for technology I don't need or the many hundreds of dollars to buy one.(hint - I am 68 yrs old, retired, and substitute teach at a high school vocational school and think the smart phone is a tool of the devil put on this earth to rot the minds of my students who would rather look at car crashes on youtube than learn something that might keep them from having to sleep under a bridge )

With that all in mind, I have thought of buying a cheap used smart phone without the cell connection and just use it as a bike computer- mp3 player- camera etc.

Is this possible?

If so, which used smart phone would be a good choice? I really don't want to spend much on this.

Any suggestions?