5 gallon tank mate suggestions

Hello all.
I am a long time lurker and first time poster. I have enjoyed reading the
different posts and opinions.

I have a 5 gallon octagon tank. It was home to a guppy and apple snail.
The guppy, which I raised from a fry, has passed on and I would like to find
another tank mate for the snail. I know a guppy likes fellow guppies so I
don't want to put another solo guppy back in the tank. I would appreciate
any suggestions as to fish that would be okay alone in a 5 gal. tank and
would be okay with the snail. I already have a Betta (in a different tank)
and would like to find something different.
Any thoughts would be appreciated.
QB