These 'magazine' don't have physical form, only exist in web and freely accessible (at least the latest chapter)

@ Vitamin
web : http://gs.dengeki.com/vitamin/
Also available on
Comic walker - https://comic-walker.com/magazine/detail/AM16/
Niconico - http://seiga.nicovideo.jp/manga/official/vitamin/
Pixiv - http://comic.pixiv.net/magazines/98/
Label : Dengeki Comic Next

Comic Newtype
formerly Niconico Ace and WebNewtype
web : https://comic.webnewtype.com/
CW - https://comic-walker.com/magazine/detail/KS12/
Nico - https://seiga.nicovideo.jp/manga/official/comicnewtype
Label : Kadokawa Comics A

Dengeki G's Comic
digital only after 2019-5 issue
web : http://gs.dengeki.com/
CW - https://comic-walker.com/magazine/detail/AM09/
Nico - https://seiga.nicovideo.jp/manga/official/gs_comic/
Label : Dengeki Comic Next

G's Comic Another
Variant of G's Comic, mainly with non-human species
web - http://gs.dengeki.com/anothers/
CW - https://comic-walker.com/magazine/detail/AM20/
Nico - http://seiga.nicovideo.jp/manga/official/gs_comic_anothers
Pixiv - https://comic.pixiv.net/magazines/247

Doradora Sharp
https://seiga.nicovideo.jp/manga/official/dradrasharp
CW - https://comic-walker.com/magazine/detail/FS04/
Label : Dragon Comics Age

Shonen Ace Plus
https://comic-walker.com/shonenaceplus/
Nico - https://seiga.nicovideo.jp/manga/official/aceplus/
Label : Kadokawa Comics A

Young Ace Up
web : https://web-ace.jp/youngaceup/
CW - https://comic-walker.com/magazine/detail/KS11/
Nico - https://seiga.nicovideo.jp/manga/official/youngaceup/

Dengeki Playstation
Full online after Vol. 686
https://denplay-comic.com/
CW - https://comic-walker.com/magazine/detail/AM19/
Nico - http://seiga.nicovideo.jp/manga/official/denplay/
Pixiv - https://comic.pixiv.net/magazines/216
Label : Dengeki Comic Next

so far I've been looking at Kadokawa, but I think there is more than that

MangaUP!
https://magazine.jp.square-enix.com/mangaup/
Not really sure since it's app-based though

Does Maga-Poke (Magazine Pocket) count?
https://pocket.shonenmagazine.com/

Kadokawa's service is Bookwalker.