The eBird app for mobile phones was launched in 2015 and now more and more birders keep track of their sightings directly on the app, while they are out in the field. The app is available for iPhone and Android phones, and has a number of very nice features, which you can read about in the main help article about eBird Mobile.
To help those new to the mobile app (and to refresh the memory of existing users!) eBirder Krishna Murthy (view his eBird profile) has put together two short and informative videos on using the app — one on the basics of using eBird Mobile, and another on more advanced tips and tricks. Do take a look, and if you find them useful, please forward along to your birding friends.
More information about the eBird Mobile app.