What are some small, strawberry size fruits to plant?

I was already getting strawberries, and heard that blackberry and raspberry were easy to grow but they are way to big. I'm interested in fruits similar in size to strawberries that are easy to grow. Any ideas? I live in Littleton, CO so its a relatively cold climate, but it is still very hot in the summer.
What are some small, strawberry size fruits to plant?
well black berries and raspberries are small in size, but they spread, if thats what you mean in size.

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