There were a number of new Latin apps for iOS and Android that I saw mentioned over the weekend.
My preferred Lewis & Short app for iOS is SPQR. When the latest version came out this fall, I wrote a review of it here. That same developer has now released SPQR for Android.
There’s also a new app for iOS that has been available for some time as a website, Logeion. The UI is a bit messy, but it is fast and free; it also combines Greek and Latin in one search field. Finally, depending on your screen size, you may find Numen a useful web app; point your mobile browser to that site, and it will explain how to “install” the interface as a separate “app” on your home screen.