 If you liked Honzuki no Gekokujou: Shisho ni Naru Tame ni wa Shudan wo Erandeiraremasen |  ...then you might like Jiisama ga Iku |
Both protagonists were reincarnated in another world from modern times and use modern inventions to improve the quality of life for people in their new world which are both akin to medieval society. Both series are incredibly sweet, wholesome and focused around children and their happiness, 'Jii-sama ga Iku' is about an old man bringing happiness to kids through sweets, toys and overall behaviour and 'Ascendance of a Bookworm' is about making books for the kids to have fun with. Both series have magic, although it isn't as prevalent in 'Ascendance of a Bookworm' in the beginning as it is in 'Jii-sama ga Iku', but