If you care, see if you can still register the name as a trademark. Maybe the other guy didn't and you can maybe show you were already using it.
THEN I might suggest you politely contact the app dev and point out that you have a fairly long standing and widely used remote app by that name and would he perhaps mind, in the interest of avoiding confusion, changing the name of his app....
Depending on his answer, and if you secured trade mark or not, you could then decide on next steps.
If you don't care, you can just change the name of yours.
: "In the United States, neither federal nor state registration is required to obtain rights in a trademark. An unregistered mark may still receive common law trademark rights. Those rights, for example, may extend to its area of influence—usually delineated by geography. As such, multiple parties may simultaneously use a mark throughout the country or even state. An unregistered mark may also be protected under the federal "Lanham Act" (15 USC 1125) prohibition against commercial misrepresentation of source or origins of goods. Unregistered marks are also protectable in the United States under Lanham Act 43(a)."
there is a third option too - not to do anything. there is no need to change the name nor to try to register it. FWIW that Remoku app in AppStore is not going to make big splash - it lacks features in other remotes by the same price (like list of channels and keyboard) and requires iOS 4.3 (WTF, with all due respect - how come other can be compatible back to iOS 3?).
Name is not everything. When i was to release my Roku remote app
to AppStore, i checked the names already in use - there is only so many ways to twist the words: RoRemote, RemoteKu, RokuMote, Romote, Remoku. I wouldn't want to use a taken name and in the end I decided on the most plainest of names: "Remote for Roku". OK, so it could have been even shorter as "Roku Remote" but that way i feel it may infringe on Roku's (TM) by sounding as if Roku (the company) has been involved or has approved in some way of the app (which they haven't). So with such a generic name, i can clearly not claim trademark on the expression "remote for roku" but i don't really care about distinguished branding; I just hope that my app will do well because of its qualities and ratings people leave.