After reading your question, I think you are a sensible and filial child. Since your grandfather lives in the countryside, he probably doesn't like those flashy things. You can give him something practical.
Does your grandfather smoke? If he does, you can give him a better pipe, or if your grandfather's legs and feet are not very flexible, you can also give him a walking stick.
In addition, you can give him health care equipment. When people get older, their health is very important. If their own health is good, they will be happy and will not add burden to the younger generation. You can give him some foot baths or massage equipment and teach him how to use them. Grandpa will be very happy because you care so much about his health, and he will definitely be happy in his heart.
Of course, you can also give some small appliances or something. After all, in the countryside, sometimes the technology is not as developed as in the city. Giving grandpa small appliances will make his daily life much more convenient.