Yes, there are. For example, some fanfictions might explore Krillin's character in new and unique ways, like giving him new powers or putting him in different situations within the Dragon Ball universe.
It probably wouldn't fit directly into the main canon as it's a rather light - hearted and comical concept. But it could exist as a side - story or an 'alternate universe' type of fanfic. It can show the characters in a more relaxed and fun - loving situation that we don't often see in the main series.
Android 16 was created by Dr. Gero. His origin story involves being designed as a powerful android with a peaceful nature. He was made to be a part of Dr. Gero's plan against Goku and the Z - fighters. Android 16 has a unique appearance and is very strong, but he doesn't have the same malicious intent as some of the other androids.
Well, one possible fanfic could be about Android 18 and Raditz teaming up against a common enemy. Maybe they initially start off as reluctant allies, but as they fight side by side, they begin to respect each other's strength.
You can try fanfiction websites such as Archive of Our Own (AO3) or FanFiction.net. They have a wide range of Dragon Ball fanfictions, and you can specifically search for Krillin SI ones using their search functions.
Goku is often paired with Android 21. Their relationship can be explored in different ways. Maybe Goku wants to test his strength against her, or they could end up training together to face a common enemy.
Goku is often paired with Android 21 in fanfictions. Their interactions can be really interesting as Goku's pure - heartedness might contrast with Android 21's more complex and conflicted nature. Vegeta is another common character paired with her. The Saiyan prince's pride and his own struggle for power could create some intense scenes when combined with Android 21's situation. Also, Android 18 is frequently paired with Android 21. Since they are both androids, they can have deep conversations about their existence and purpose.
A really interesting fanfic idea could be set in a post - apocalyptic version of the Dragon Ball universe. Android 18 and Krillin have to fight to protect the few remaining survivors. They use their unique skills, with Android 18's android powers and Krillin's martial arts. Their relationship becomes a source of hope for those around them, as they prove that love can still exist even in the harshest of times.
Perhaps in the fanfic, Android 18 uses her combat skills to train Raditz. Since she has a lot of fighting experience, she could help Raditz improve his techniques. This could lead to an interesting dynamic where Raditz becomes more powerful under her guidance.
There are many great writers out there. Some popular ones are often those who have a deep understanding of the Dragon Ball Z universe. They can capture the essence of Android 17 and 18's characters really well. However, it's hard to name just a few as there are so many talented fanfiction writers in the community.