I'm currently developing a webapp for language learning in the hopes of turning it into a profitable business. I've been mulling over a certain name for a while though I've looked through the google play store and chrome add-on store and both have apps named virtually the same thing. They're all still in the same domain as mine (language learning with emphasis on vocab retention), but none of them have been updated in the last few years and they all have very few users/downloads. None of them seem to be trademarked.
If I ended up using this name and it takes off, should I be concerned about any of this?