I have the Dream app. There is an option for air conditioner, rain, waves, fire, etc. I turn them all on. You could also just get an old click radio and tune it to static. Works really well and doesn't require a special device!
I use Relax M HD. I love it and it's free! It has a vacuum sound. Plus you can mix sounds together.
For example, I will mix white noise and rain, but I will make the rain a little louder than the white noise. Plus it takes up like 2% of the battery through the whole night.
ETA that was the name showing up on the app, but I just looked it up in the App Store it's "relax melodies HD: sleep zen sounds..."
Just FYI, we face it away from the crib so it's not blowing on them. Well, I should say it doesn't blow on DD2. DD1, though, prefers to sleep on the floor in front of her fan instead of in her bed. Lol. Ah 2/3 year olds. They certainly keep you guessing.
Re: White Noise
We have this one too
We have this one.
https://www.amazon.com/gp/aw/d/B006O4SF8A/ref=mp_s_a_1_1?qid=1399843492&sr=8-1&pi=SY200_QL40
I haven't tried it before, but we do have one.