There's an app for just about anything these days -- but this "Relax and Sleep" (a favorite free Android app of mine) is one I've recommended to friends who travel and find it hard to get to sleep when they're away from home. Think of it as your own personal, free, environmental ambiance generator -- and so much more.
Need a free white noise generator to help you doze off? Yes, "Relax and Sleep" has an assortment of white noise type generators, inclluding "fan" and "washing machine." I prefer to combine several sounds together (my favorite is rain and a cat purring, along with cricket frogs) to create a lovely soundscape as I drift off to sleep. However, you can also use it to create a work-friendly soundscape to help you focus your attention and minimize distractions from the rest of your workspace.
Here's the link to the free version for the Android operating system -- BUT -- it's such a lovely little app that
I recommend paying the $3.00 and getting the paid version.
And happy napping!