Aww its cute! I agree, looks like a bladder snail to me. They aren't much of a problem if you feed light and keep your detritus siphoned up.
With a ten gallon there aren't a lot of options, don't listen to the box stores on what you can have. Majority of their suggestions are not good for 10 gallon tanks.
Endlers would be an option, as would ember tetras. A male betta on his own would likely take up majority of the space. A paradise fish is another option, if you can find them. You could also do some inverts, like cherry shrimp and some celestial pearl danios or something that size.