I'm kinda interested in it, lately. I've read Boku dake ga inai Machi, ib - Instant Bullet and I also liked Skip! Yamada-kun
I don't mind any genres, one-shot or serialized. As long as it's centered/involved time travel! Thank you!

Little Jumper

Amatsuki
Babel (INOUE Noriyoshi)
Bouken Shounen
Fushigi na Shounen
Asuka @ Miraikei
Thermae Romae
Golden Days
Gyakusou Shoujo - Owaranai Natsuyasumi
Black Cat Tunnel
Heptagon
The title story from Akatsuki no Fumi
Haruka na Machi e
Hi no Tori
Mikake no Nijuusei
Mirai no Football
Nanase
Sengoku Jieitai 1549
Sprite
Suzumiya Haruhi no Yuuutsu
Suiiki
Toki no Shoushitsu Ukeoinin
Yokohamasen Doppelganger
Threads of Time
Wish
Zipang
STEINS; GATE, but I recommend the anime over the manga. Ditto for Buddy Complex.

And if you don't mind light novels:
Utsuro no Hako to Zero no Maria (Novel)
Feng Yu Jiu Tian (Novel)

Will add more if I remember.

As you aren't picky about genre, I recommend a category search for "Time travel" and "Time traveler/s." That'll turn up a lot of titles you won't get through user recs alone.

Red River
Kanata Kara
Fushigi Yuugi
Yukarism
Kateikyoushi Hitman Reborn!
Ryuurouden
Kamikaze Kaitou Jeanne
Rave
Sengoku Strays
Saver

I'm not really sure if these are the types you're looking for but... they're just some suggestions if you're interested.
I wasn't sure what sort of genre you liked so there's a mix of everything..

Thanks for all those recommendations! I'll go try reading those that's interesting 😀

Omoide Konpeitou - oneshot
Shinobi Life

if you are okay with BL:
≠ - Not Equal
Nemureru Tsuki

Rure
Seol Hui
If only someone would finish scanlating these....