Colour-code calls by recency

[rosslh]

It would be useful if the map showed which calls occurred in, say, the last 30 minutes.

[rdrnt]

Hi! Thanks for the feedback. I really appreciate it.

Currently I'm not pushing any new updates to the current version, as I'm re-writing the project from the ground up. I'll definitely keep this in mind, I think this would be a helpful feature to have for the next release.