What is the meaning of the word "überrannt"? whenever I search for for it in any dictionary, it ends by the verb überrennen.
it ends by the verb überrennen.
"überrannt" is the past of "überrennen".
In this phrase "überrannt" is the passive form of "überrennen", that's why dictionaries take you there.
In this context "überrennen" is figurative. It means something comes quite fast and unexpected, it overstrains one's mind or capabilities. There is no time to get prepared and react appropriately to a situation.
I think this expression has no present form, there is only this past form "überrannt werden".
Perhaps these two phrases shall say: the smartphones came too fast, there was no chance to prepare and handling them is too much for the people.
It's not this question's topic but the second phrase is wrong. It must be "über ihren". It still sounds odd to me, I have no exact idea what this phrase wants to express.
I searched for this phrase and found an article that could be your source.
It talks about an app that examines user behavior on smartphones.
"wir wurden überrannt" - they didn't expect so many users would join this research and use the app.
Then: this (the amount of people that joined) shows that ...