Seeking Fantasy Novels in the Modern Magic genre

Take a look at Max Gladstone's Craft series, that might be just what you are looking for. Not quite cell-phone modern but they do have alternatives to such technology.

My favorite series: Young Wizards. Start with So You Want To Be A Wizard?

The author also has a one-off, Stealing the Elf King's Roses, which fits your request and some of her short stories cover other modern-day fantasy stuff.

In neither of these does magic entirely replace technology (in the Earth of YW wizardry is underground though there are other parts of the setting where it's not) but there is a blending of tech and magic-powered tech. In Young Wizards this starts coming out more with the third book, High Wizardry, but I don't recommend skipping around in the series. I'll also add that there are two editions - the New Millennium Editions available from the author's online store are updated versions that correct timeline ambiguities that came from the first books being written back in the 80s.

The Incarnations of Immortality by Piers Anthony is kind of what your asking for, but the world building around the magical technology isn't really emphasized in depth at all.

If you don't mind something with a futuristic bent, the Shadowrun tabletop RPG got a series of novelizations. It's all about our world in the 2080s when a big event sort of brings back fantasy into our modern world, so suddenly there are dragons, orcs, elves but you still have hackers and armed mercenaries with sniper rifles. It's more of a coexistence between fantasy and science fiction.